I have some practical advice for dealing with reflux day to day which may or may not help you.
I found that if I ever put my dd lying flat on her back she would scream and scream as acid would come up so I had to avoid doing this as much as possible.
Nappy changes were probably the only time I did so and even then I tried to keep her on a tilt with head up. I used one of those wedge pillows previously mentioned.
For her moses and carry cot on pushachair what I did was propped the head of it up using rolled up blankets or even books at home under the mattress at around a 45 degree incline.
She never slept until we had sorted the dairy elimination and meds (the same ones as you have domp and ranitidine) and the only way she did sleep was on her front as it took the pressure off her gut. Obviously front sleeping is not recommended by health professionals now due to SIDS however this was a decision based on zero sleep or she would get a few hours so a no brainer for us really.
You could try it for a nap and watch him to see how you get on.
Waterproof sheets on your mattresses are your friend, I also layered up sheets and muslin clothes alternated in the cot bit when we went out to mean that if she vomited on her sheets I only had to peel off the first layer and there were other sheets underneath still dry.
Make sure you go back and get him weighed every 7 to 10 days regarding his dosage of meds. They grow out of their dosage so quickly at that age so you need to keep on top of it.
For bathing, I found this miraculous thing called a tummy tub which is a smooth bucket and meant she was standing up to be bathed.
I carried her around a lot in a moby wrap sling forward to my chest with legs out. If I walked briskly the motion of this often sent her to sleep.
When she was frantic screaming in pain I often blasted out white noise, loudly and this calmed her.
There are videos on youtube of the audio.
I will add anything else I think of x