My dd is now 4 mths old, although, like you, I was very aware of the symptoms and she had everyone of them too from 3 wks, she was formerly diagnosed with silent reflux and colic when she was 6wks old.
What worked for us (after much trial and error) was putting her on her tummy to sleep (at 3 wks), switching to Nan HA Gold formula, Dr prescribed Zoton medication & we also took her to a paediatric chiropractor that specialises in babies with reflux. Along with that, there are the other guidelines like sitting them upright for 20mins after a feed and having the bed (whether bassinet or cot) raised at the "head" end.
I hope this helps and wish you all the best with your bub. Feel free to pm me if you like.