I need to vent. Idk what to do

So I've spent what felt like a pretty great time in a great relationship. Yeah we had our ups and downs. But that is normal. I'm very angry right now. Angry because I've done so much and supported him through so much. He has PKD. Polycystic kidney disease. Has had it for 10 years now. On dialysis 4x a week recently just had his last remaining kidney removed so he has no kidneys. Was there for dialysis, appts, and surgeries. Not to mention countless ER visits and hospital stays. Lately he's been starting pointless fights. Oh I also didn't mention he lives 50miles from me. I would make that trip many times a week. That is $20 in gas each trip. And the other day I tell him this week I prob can't visit as much because of Xmas my work schedule and I still have gifts to buy and he goes on this rant how I don't listen to him his feelings mean nothing I don't support him. We haven't talked since and I'm going crazy. He's being so selfish and I told him that. Idk what to do. Do I just let him be? I mean I shouldn't be going through this in my 30s. We're both too old for this. I just needed to vent. I feel like I can't talk to anyone. Because we were so good.