Hi hun - sorry to hear you're going through this - it sounds like the classic reflux symptoms to me. I would def go to your doc or health visitor. Is he being sick with it? If so they can prescribe thicker formula if you FF, or gaviscon as well (I think that can be used too if BF, not 100% sure though).
We had to try a few medications before it helped Amy, ended up on losec and it's worked great.
Just try and keep your Lo as upright as poss when feeding.
As some of the other ladies have said, try and put something under the head of the cot to raise him up slightly.
I know it is really hard, I cried most days before we found the right solution for Amy, but def speak to your doc. xxx