15 week old sleep problems HELP

My 15 week old has been sleeping terrible for around 3 weeks now. He was sick for about 5 days so i figured that was why, but now he’s been completely better and is still not sleeping.

Tonight he has woken up every two hours and is crying like he’s in pain. I tried feeding him and he drank a couple of ounces and then started stiffening his whole body while crying even while i tried to rock him back to sleep?

Could this be gas? He is gassy throughout the day but i try to limit gas drops i give him. Sleep regression? Something else? I am losing my mind with the lack of sleep plus i work full time now and it’s so hard!!!

I bought him a new swaddle that I’m going to see if it helps. (The one to transition him from a regular swaddle since i can’t swaddle him anymore)

Any suggestions?! I’ll try anything!!!