Colicky baby

So my 5 week old is very colicky, we cry from 5am to 10 30 pm every day with 10 to 15 min naps. Every feed all he wants to eat is 1 oz to 2 oz ( very lucky if we get three oz) the doctor has but him on a acid reflux prescription and he has been on it for a week (no difference still spits up a lot (looks like whole meal) and screams after a burp) he is also taking gas drops and gripe water. I’m thinking about trying a probiotic but I don’t know if I’ll be giving him too many things to try and help also don’t know if he is old enough for a probiotic? He is formula feed (enfamil gentle ease. Doctor wants him staying on this formula as we have tried four different kinds already ( good start, soy based one, and similac) he also poops every other day. Do you think the probiotic is worth a shot or is it too much for him. Also what kind of probiotic would be good for a 5 week old? FTM thanks