please help

I am 21 years old and I live with my boyfriend, also 21, who suffers from epilepsy. He was diagnosed in 9th grade and has kept his seizures quite managed for the years since then. We have been dating for almost a year now and I have witnessed him have multiple seizures stemming from vairous causes (most of which could have been avoided if he had been taking care of himself health-wise) which I know are bound to happen. But lately it seems whenever we have a serious fight it always ends with him having a seizure. Now I know that epilepsy is a neurlogical disorder and that his seizures are not my fault, but I cannot help but feel immensely guilty whenever this happens. I don't know what to do in order to avoid this, but it just has a negative psychological toll on myself as well. I feel like I cannot express myself to him if it's going to end in a fight because I care more about him and doing anything to prevent from having a seizure rather than be able to be open. /: