Baby problems

Hello,

I have a 12 weeks old baby boy and he has a few problems : tummy cramps while eating (i suppose as he stops eating and cries),explosive poo, cradle cap, dry skin.

History/health
-ventouse delivery (prolongued second stage)
-antibiotics during labour (diagnosed with GBS)
-no jaundice
-3.5 kg at birth; good weight gain but didn't get chubby
-was circumcised at 5 days
-almost exclusively breasfed
-very gasy - needs to be burped during feeds;
-stops eating and starts crying, needs to burp/pass gas
-blocked nose from birth
-got a cold(very blocked nose and chest cough) at 8 weeks and was given antibiotics - after this he got diarrhea, green stools, dry skin, cradle cap;his weight gain slowe down; I gave him Solgar probiotics a ,few times, his stools got better colorwise but very explosive, they get out of his nappy
-suffered from colics - bad pains a couple of hours in the evenigs - seems better since we have seen a cranial osteopath a few days ago - we are still waiting to see if they return


Appearance
-he is very fair even if he is mixed background (eastern European & Egyptian)
-light brown hair (very few)
-no defined eyes color yet(dark grey)
-bigger head that usual - (was supervised for hydrocaephalus but the scans look fine so far)

Character
-used to sleep quite well during the night even from begining
-he was very frantic eater, calmed down a bit
-he screams really bad when he's hungry; dirty nappies don't bother him very much
-he loves to play on his own looking at toys
-used to fall asleep by himself in the buggy or held by hend in his cot but after he was ill he got used to fall asleep only held in arms
-chews his fists
-loves cooing

I really hope that I can get some help!
Thank you!