<human>: Can you condense the text into a few key points?

I barely know where to start. Ive been with this man for about 1 1/2 now. Through our whole relationship he has struggled with family problems. His brother is a bad alcoholic. His dad needs his help a lot cause he's elderly etc. He dedicates basically all his time to them. His brother has been in and out of the hospital due to alcohol related problems and is in again right now. They say he probably doesnt have much longer to live, maybe a year or so depending I guess. 

My boyfriend is incredibly hurt right now. Hurting so bad. I know our relationship just adds extra stress to him cause I have needs too. I've been very understanding through this whole thing though. I know I have to come second. I know the best thing I could do for him is end our relationship. But I'm so in love with him. The thought of losing him makes my world feel like its crumbling. I can't stop crying. Our relationship is great besides all this. We're awesome as a couple. We've talked about marriage, kids, living together this year. Before this last hospital incident.  

My question is how do I let him go when I don't want to? I feel like itd be the best thing I could for him. But deep down I don't want to at all. I'm so in love with him. I guess I'm just fighting between being selfless and selfish.
<bot>: boyfriend going through major family struggles. I feel it's probably best for me to end everything so he'll have one less stress. But I love him and the though of losing him is breaking my heart.