Hi Mia

First, sadly it is very possible that he has forgotten what the nipple is for. One week after I stopped nursing Brayton at 12 months old, he needed comforting (he fell?? was teething?? I forget) and I offered my breast to him and he did what it sounds like Riley is doing. I couldn't believe he would forget that quickly, I mean it was only a week after we stopped!
Relactation is a possibility, but it is VERY HARD. I'm not saying that to discourage you, but I had unrealistic expectations when I tried relactating 6 weeks after I stopped nursing Dawson. The online accounts I read sounded so simple -- just put him back at the breast, pump some, and my milk would come back. Seemed easy enough! The problem with that is that my body had changed and the hormones for milk production were gone and were replaced by the hormones for starting my period. Plus, Dawson would not latch on at all. I tried a supplemental feeding tube but he refused. I was ok with just pumping, thinking that if I just got enough milk in with pumping that maybe he would take the breast if he was rewarded with milk, or at least be able to give him EBM. Unfortunately, that didn't work out either because I wasn't able to dedicate the time it takes to do that (pumping for 15 minutes every 2 hours for weeks isn't realistic with two other kids!). I was able to pump out some fluid, but it never brought the milk back in.
I spoke with 2 different LLL leaders, and they were both very supportive even though neither of them had ever known anyone who successfully relactated. I worked with a lactation consultant at the Sentara Women's Center and at her suggestion rented the Medela Symphony because she said anything less just wouldn't be enough suction to get things going again ($60 for attachments plus $75 per month). I spoke with my midwife and explained what I was doing and asked for a prescription for Reglan (ideally I would have gotten Domparidone but it's not available in this country), but that just didn't work for me. I was told by several people that however long it has been since you stopped nursing, it takes about that long again for your milk to come in.
I finally came to the realization that it just wasn't meant to be for me. And I'm ok with it.
You knew me back in the days when I was very much a breastfeeding supporter (borderline lactivist) -- think back to when Jordan was born! And I know how much you wanted to nurse Riley for an extended time, but my honest advice is to look at the whole picture. Look at where you are right now -- you have a lot on your plate! I bet Riley is getting pretty mobile, wanting to explore, and I *know* things are more stressful with DH gone. Now look at where you have been -- look at all of the breastfeeding issues you overcame early on with Riley! You have provided him with many months of breastmilk which is very commendable given his illnesses, etc. Now look ahead to the next couple of months -- and decide how much it means to you to get back to breastfeeding. If it is something that you really want to make a priority, then do it! I'd be happy to send you the info on the Women's Center. If you decide not to, don't beat yourself up about it. I know this is the breastfeeding forum and what you are asking for is help, but from me you get advice instead.