My 4 mo won’t go to sleep before 10pm

I’m seriously at a loss. Sleep has been so challenging for us since day 1. We have needed to contact nap and co-sleep as this baby refuses to be put down in his bassinet or crib. When we’ve tried, he will either wake up immediately or sleep for 10 minutes and he will start thrashing and it can’t be saved. The longest I’ve ever had him nap in his crib is 30 minutes. I thought my first born was a bad sleeper, but he is something else.

Our wake windows start out at 1.5 then increase to 2 hours by the evening. He generally takes 4 naps, typically between 60-90 minutes. But regardless, refuses to go to bed before 10pm.

His overnight sleep is also crap. Most nights he gives me 90 minutes, but the odd time he will sleep for 2.5-3 hours. I think he has only slept 4 hours one time. He is so squirmy and thrashy overnight - I end up giving him bum taps for a good chunk of the night or else he wakes up.

I’m so exhausted. I have a very busy toddler and my husband works shift work so I’m often solo parenting.

I don’t know what I’m doing wrong but I’m open to any and all suggestions!!