Sorry I can't help really but wanted you to know you are not alone. Almost everyone, including me, that I speak to with a baby this age says the same. I believe it's a result of the changes to babies sleep at around 4 months, they now sleep like us which means they wake every 30-45 mins and have to resettle. If they need help to settle in the first place t he y will expect this help each time they wake!
My lo self settles and sleeps all night like this, but our naps are shocking unless I lay with her, she too will only cat nap and by bedtime is ot and cranky, hence lying with her to keep everyone happy. I am in the process of trying white noise but I'm not quite convinced yet. I'm hoping that when she can stay awake longer in the day naps will start to consolidate again. It's so upsetting when you have a good napper and then not. I wouldn't mind, my lo took forever to even settle out of my arms since birth, then around 11 weeks we seemed to crack it, only to be snatched away again at 16 weeks
I wish there was an easy answer out there.