My son is 19 weeks old and I'm assuming what we are experiencing is a sleep regression. He is working on rolling (and is so close), discovered his lips as he now lips smacks constantly and is drooling like crazy (possibly teething?). We put him to bed around 7pm and he sleeps great until 10:30-12am then he is up every 30-60 minutes until 6am when I finally give up. As soon as I pick him up he either snuggles in my arm and goes back to sleep or he acts hungry but as soon as I give him a bottle he drinks for 30 seconds then doesn't want anymore. In either situation it takes up to an hour to get him back to sleep as every time I lay him down he wakes up crying. He sleeps in our room in his bassinet. We have blackout curtains, white noise & keep it cool. He uses a sleepsack. Anything else we should do or try? I'm absolutely exhausted with only 2-3 hours of sleep a night and am barely functioning now that it's been over a week.

Edit: bed sharing is not a safe option for us & sleeping while baby is asleep is also not an option (we have a 2.5 year old who no longer naps).