I have a touchy child who also has a lot of trouble separating. In your case I can't quite tell if it's a separation issue that's constant due to a personality issue, or if this is a situational thing or attention getting problem.
Have you noticed any other unusual behaviors? for instance, does he have trouble touching certain textures or accepting new foods? Is he socially shy or resistant to touch from strangers or even familiar friends and family?I have a feeling your going away isn't as 'without problem' as you thought. A lot of times kids don't show any issues at the time a parent is away, but what happens is they internalize those feelings and it comes out behaviorally later. For example, I took my son on a trip away from home leaving DH behind for 5 days; he was almost the exact same age as your son (22 mo). Owen had a great time on our trip, and didn't seem to miss daddy all that much. HOwever, when we got home Owen lost his little mind anytime Daddy tried to take him in the car -- just to the grocery or whatever. It was totally out of the blue as before our trip Owen LOVED going grocery shopping with daddy. We eventually figured out that Owen was worried daddy would take him on a trip without me unexpectedly! He also freaked out whenever he saw suitcases. It took 6-9 months for us to slowly get him to calm down.
I guess what I 'm getting at is I believe your occasional nights away have taken their toll and have made him both worried that you're going to leave and perhaps a bit angry. He's not even 2! He's so young that he probably doesn't even understand why he feels the way he does.
I think one thing I might do is stretch out his wind down ritual a bit more. Make sure the ritual is EXACTLY the same every night so that the moment for sleep isn't a surprise. Make it a big longer than you have been, perhaps ending with you hanging out by his crib or bed, talking about his day, singing a song, telling a made-up story in which he is the star. Just something that is very upbeat and loving to prolong your time together in a positive way. Also, you might want to start giving him lots of warnings for when bedtime ritual is going to happen -- at our house we set the timer on the microwave for "Last 5 minutes" so that Owen knows he has 5 more minutes of play. Then during your bedtime ritual you might say "Ok, after bath we are going to read stories and cuddle and then it will be time to sleep!" and then "After stories we will cuddle and then it is time to sleep!" "After our cuddle it will be time to sleep!" just so he has verbal warnings of what is to come next and how far he is from the sleeping part of it.
I also want you to start verbalizing "Sometimes mommy goes into the other room, but she always comes back!" This may seem silly, but hearing this over and over makes them start ot believe it so that they don't get the same panicked feeling whenever mommy leaves. At night time I want you to also say something right before you leave that goes a bit like "It's time for ____ to go to sleep now. Mommy is just going to be in her room sleeping too. If you need her she will always come back. And then when you wake up in the morning we'll have a big hug and kiss to start our day! Mommy will see you in the morning! I love you!" In other words remind him that you are just down the hall or whatever and that you will always be there for him if he needs you. That is to this day my son's favorite phrase from our wind down, and he will offer up himself "Mommy comes if I need her!" because it's such an important concept for him. Sounds like your son needs this reassurance as well.
Then, I think it's important to watch your behavior when he has his meltdowns/fits because of being separated from you. We want to offer him love and reassurance, but we also want to make sure we're not rewarding negative behavior. I wnat you to start 'catching him doing something right'. In other words, if you go in the other room to do laundry and he behaves well you need to really celebrate it when you come back. "Wow! You're such a big boy! Mommy went in the other room and you just played like a big boy! Well done sweetheart!" then lots of hugs and kisses. When you are leaving and he pitches a fit you need to make sure that you have a calm expression while you handle it. So you give him hugs and kisses and say "You know mommy loves you no matter what. But mommy has to go now. I know you will have lots of fun with Nanny. I'll see you soon! *hugs, kisses*" Very positive, but without any emotion or "Oh honey, poor dear. I know this hard..." etc. etc. You wil behave as if it is no big deal for you to leave because you come back. Then when you do come back you'll say "mOmmys back! See! Mommy ALWAYS comes back! I love you and I'm proud of you for being so big while I was gone!" You might even want to give him a sticker when you come back so that he associates mommy leaving with getting a small reward when she comes back. Even if he cries when you leave give him a sticker when you come home and praise him for being a big boy.
As for independent playing, that's a bit tough because he's STILL rather young. You might be expecting a little too much from him. He's a boy and i"m afraid they tend to enter the independent play stage a bit later than girls do. They are SO dependent on mommy's for approval and affection. Tehy really need us! So what I would suggest instead is to try involving him more in what YOU'RE doing -- have him 'help' with dinner (we got my son something called the "Learning Tower" so that he could safely stand at the counters without worry of him getting hurt), help with laundry, help dust the furniture or 'sort socks' (he'll just mash 'em around, but it will keep him busy!). Have him participate in what you're doing and he'll be so happy! You can also get him started playing with something, and have him do it near you -- like give him some playdough to work while you are making dinner. Talk and interact with him while you're doing 2 different activities. I think if he senses you are trying to make him play independently it will get him worried that you are about to abandon him by going off somewhere. So involve him! He will slowly become more independent with time. He's just too young right now to be very good at it. But there's a million ways to make him a part of what you're doing so that he's happy AND you're getting stuff done.
Some kids just don't do well with separation. I have one of those. We took it slow and i must say that has paid off a million times over. My son is nearly 4 and started preschool this fall. It was his first time being away from me with strangers. We've had babysitters etc., but most of them sit while I"m home working so he's never truly away from me. But after a hard first 5 minutes of school he's done fantastically well! And I truly think it's because I never forced him to do more separating than he was ready for.
I'm hoping that extending wind down and giving him more time to transition that bedtime will go well. Some kids just don't transition well; these children also tend to be the ones who have trouble separating! I think the two go hand-in-hand. So, give him a longer wind down and verbally and audibly provide him cues as to how close sleep time is. Give him longer time with you prior to leaving his room to adjust to the idea that it is time to separate for sleep. And I think that will go a long way towards helping this. I suspect the reason all of this is directed at you is linked to your going away overnight several times in his life. Yes, he can handle it when you're gone. But it's taken away his surety that you will be there when he wakes up. So, he's afraid to say goodnight for fear that when he wakes up someone else will be there. I think that is reasonable given his experience, so let's talk to him and reassure him that mommy is going to be there, no worries. Verbalizing is so helpful because they really believe what we say. I think if you put words to his worries it will help take the burden off his shoulders.
HTH! And let me know if you put any of these ideas to work and how you get on!
