extreme slow physical developlment.

[salinyaingo1]

hi.
i delivered my first born baby boy premature at 29 weeks old on 19th december 2014 with 1.2kgs. my pregnancy was normal but i suddenly had premature labour and forced to deliver my son through c.s. he cried but then stopped coz of lack of oxygen and he spent 43days in the incubator and 4 weeks using oxygen most of the time. he hasnt been sick after being discharged but has been very slow in development. he eats very well, looks very healthy and at 14months has 7teeth. he recently started talking and trying to hold his head up but slightly falls on the side again. he cant sit, crawl, stand and walk. i visited his ped and he tested his calcium levels and said he was fine. they took a wrist xray to cjeck for rickets and he was okay. he refered me to the O.T for check up and the o.t said he has hypotonia. hes been to therapy for 2months but no improvements. he hates tummy time and cries hysterically. he can only roll from tummy to back coz he hates being on his tummy. i give him massages at home and exercise most of the time with him like teaching him to roll, putting his toes in mouth, rubbing his foot together and hand with foot. im worried sick i cry most nights and day. please help. what might be wrong???
nairobi, kenya