Welcome. I'm sorry that you've had to struggle with cerebal palsy, seizures and migraines. That sounds like a lot to deal with as a child and then growing up. It takes a strong person to handle these.
Unfortunately, I don't think it's possible to respond only to the visual part of your migraines. I experience visual acuities with my migraines and I have never been able to separate the two. Unfortunately, you may find as you get older that the migraines get more severe.
As you may or may not know, chocolate, milk, eggs, cheese, sausage, pop, chips and dip are all potential triggers for migraines, as well as alcohol and smoking. I used to drink alcohol socially at your age and had friends that smoked around me. I know suffer migraines daily when I'm not on medication and it has become to important to me to eat these things, drink or be around people who smoke. My health is very important and I don't want to suffer chronic migraines, so I have cut these things out of my life.
My stepmother suffers from Epilepsy. It is a symptom of her MS. She doesn't suffer many seizures but I know they scare her. I also know if she knew what could prevent them she would do anything to stop them.
You may find as you get older that your health is more important than fitting in and that your friends will respect all the more for not engaging in activities that make your illnesses worse. That way you don't have to experience the auras, the migraines and possibly the seizures.
I wish you all the best. Let us know how your search for a solution goes.