Help!!! My 3 month old WILL NOT sleep longer than 2 hours...

My son is 3 and a half months old. He was sleeping for 4-5 hours at a times and only waking up to feed, and then going straight back down to bed. I got him on a scheduled bed time, which he knew and would go down for the night with.

For about a week now everything has changed!!! He wakes up every hour- 2 hours and sometimes doesn’t even go back to bed for a bit. I am SO exhausted. I don’t know what to do.

I believe he is starting to teethe, his gums feel swollen, but he’s not super cranky and he still has his naps during the day.

He is still sleeping in his bassinet and seems to be getting too big for it, could this be a reason? I’m planning on moving his crib in our room tomorrow.

What do you think this is? I’m losing my mind here!!!! I’m so exhausted and frustrated 😭