I feel really guilty about this.
Do you actually feel guilty about your boyfriend's illness?
Yes, I feel very sad when I'm with him because I hate witnessing his pain.
I'm sorry your boyfriend is feeling that ill, but if you are that guilty you need to still talk to him. You don't know if this may be the last time, and you need to give out all your honesty before it's too late.
I've been spending much time with him and I want to ease his symptoms. I've already given in my all to his condition for a long time and I just can't face it anymore.
If you are overwhelmed, you should consider a break for a day or two, but abandoning him would not be the right choice at this time.