7 month old WONT SLEEP 😭😭

My son just turned 7 months old. In the last month he has learned how to crawl and sit up after being laid down. So now in the middle of the night he sits straight up and can't figure out how to get comfy again, which means he's up like every 2 hours. And then he takes at least an hour to fall back asleep. I don't go get him until he starts screaming, but he has "played" for over an hour and just can't fall asleep once he's sitting up, he has tried by just hunching himself over but at that point he's so tired he gets all worked up and starts crying. I'm assuming the sitting up is the problem because he used to sleep 10-12 hours with just one wake up in between for a bottle. And after that bottle I used to just lay him back down and he'd put himself back to sleep. But not anymore . Now he's pretty much only sleeping a total of 6 hours a night cause he's waking up so much and can hardly put himself back to sleep. Any suggestions?! We're both exhausted and I just don't know what to do 😭 we're going on 2 weeks of this now.