Does my child have migraines? Help please

Hello
I will try to be brief! My son,aged 9,was born at term. Within 24 hours of birth he was covered in a rash. GP said baby acne I thought it was more like eczema . Diarrhoea and vomiting then started and gradually got worse until at 7 weeks he went onto soya milk. All symptoms stopped overnight and he was a completely healthy baby. At 6 months he had solids with dairy and had no problem. At 12 months I put him onto cows milk and no problems. At aged 2 he started nursery and started having tummy bug. The first 2 of these I thought were due to new germs at nursery. After a couple of these I realised only my son was catching these bugs and not myself or other children. The bugs lasted 2 days and had lots of vomiting and diarrhoea. The diarrhoea would continue until all dairy was eradicated out of his diet (Gp’s advice) we just presumed he wasn’t totally out of his dairy intolerance. Gp said that as the bugs were only every 2 months then it was worth continuing having milk in his diet. Eventually these episodes,over the years,became much more intense and grew a lot shorter but more of them. He was having them every month. He would get a feeling it was happening would vomit up to 20 times in an hour. Then have severe head pains and go into a semi vegetative state for a few hours. We had many hospital visits,always put down to gastroenteritis. We have only on the last 12 months been referred to a consultant and he was diagnosed with cyclical vomiting syndrome. The consultant has now changed his mind and said migraines. He is on pizotifen which has helped until 2 months ago and he got worse so they upped his dose and it worked again for a few weeks and now he has had 3 episodes in 10 days. They are always brought on by physical activity or heat. He can’t even manage sports days or parties. It’s so upsetting for him and my other children as we always have to leave early. When he feels an episode coming on he takes a zofran melt and this will hold it off so compared to a few months ago when he wasn’t on any medication then things are better but they are happening a lot more now but being stopped by medication which doesn’t feel the right answer for a child so young. The only tests he has had are blood tests which showed some mild allergies. The highest one was wheat so he is now gluten free,on dieticians advice. We saw his nurse yesterday and she is going to contact his neurologist and gastro consultant to tell them he isn’t doing very well but I doubt wether they will see him anytime soon. Thanks for reading! Sorry it’s so long but any advice would be amazing as we are really struggling!