Poor breastfeeding. I take him to!

My son is 2 months 20 days old. For two months he had been taking proper breastfeed for around 20-25 mins after every 2-౩ hours but from the past 19-20 days, he is poorly feeding.. he feeds for just 4 to 5 mins and goes without feed for 7-8 hours at times. The more severe thing is that he does not latch properly but if he does then after 4-5 mins he would pull back his head vigorously, his eyes go crossed and he repeatedly bangs his hand. It appeared to us as a seizure but we consulted a neurologist and she got done his MRI brain and EEG for 20 mins and the reports were normal.. And she said that a seizure is not time specific.. so it can come anytime, not just while breastfeeding. At all times he remains active and playful but feeds very poorly. Every doctor I take him to regarding this concern says that he is absolutely fine.. But I can observe clearly the difference in his feeding pattern and I'm worried he might be starving. kindly suggest what can be done.