Hi, Emma, sweetie
Hiya is right...no one here will call you stupid and I know that you are worried about your ex's illness and how he won't have much longer to live. I also know how you wish to be the one holding his hand when his time comes and perhaps you will find a way that you can still do that without losing your self respect and dignity in the process.
Like Hiya mentioned, in order to do so you are going to have to accept the fact that he is no longer able to be your BF, for sometime now I have felt that he doesn't want to hurt you by dying and not being able to be with you. In fact, for people who are dying it is so very difficult for them to be with someone who is so full of life and a reminder of what they will be missing out on and perhaps that is what he sees with you. Funny how his GF has the same illness.....he doesn't have to feel that way when he is with somebody who has the same fate as him. Whereas with you he has to face the pain of not being able to be healthy or have all the wonderful things a future holds that he will never have. It seems that everytime he treats you badly he has just come from the doctor who told him some more bad news.
You need to accept that he cannot be with you without feeling bad about his life and the shortness of it. You do not deserve to be treated so poorly by him and I know that if you were to tell his GF about everything it would not make you feel any better like you think it would. No...you are too good a person to do that.
Instead I think you need to take care of yourself and continue your studies and not allow this to diminish your self worth. You are a wonderful young lady who deserves to be happy. Focusing on yourself right now is so important. Distance yourself from our BF and perhaps in time he will realize how poorly he has treated you and that he does so because of his turmoil and anger towards his prognosis and chronic illness that will eventually take his life. He will realize this one day Emma and see how he has pushed you away because of his inner pain with the entire situation. Give him the space to be able to see this and while you do take care of yourself so that you can feel good again.
I know that this will not be an easy thing to do because of how much you care about him, but it is important that you do. Please know that we are here for you during the times you find it difficult to do so. And know that we have plenty of (((HUGS))) to send your way. ~ Goody