Worried about my (21f) boyfriends (25m) health, how do I bring this up in a caring and gentle but serious way?

We have been together for about 8 months now. He has been drinking since I’ve known him but he usually drinks only on the weekends and cons but when he does sometimes he can go a bit overboard especially when we go to cons. He never gets negative or anything when drunk, actually he gets more charming and sweet but im genuinely concerned for this health especially as of late.

I brought up the last few weeks I’ve needed to sort out my health ie lose weight, exercise and cut out my alcohol completely unless its a special occasion like my birthday, or our anniversary or a con, but when I do I drink light because I am a lightweight it seems. I have fatty liver so I shouldn’t even be drinking much.
I’ve gone to my boyfriend saying Im not sure how to go about trying to lose weight sometimes because I really haven’t had much exercise as bad as it sounds and he said maybe we can do walks together (even on days we aren’t hanging out, like try to go on walks or something around the same time) but onto the main thing..

We were texting this morning and it came up my boyfriend was gonna go on walks more because it feels like he’s dying, he’s been so tired and he feels like he’s actively dying. I didnt pry into this much but I wanted to support him and help him any way I can. I didnt bring up anything like cutting alcohol (as he is trying to drink less when he does but I think he needs to stop completely for his health, I’m worried about his liver) or weight as he’s a bit bigger which i love personally but I truly want to make sure he is healthy. Him saying he felt like he was dying scared me.

Do I bring this up? Im not sure how and i just don’t want it to seem attacking or anything when its stuff he may already know he has to do and is aware of. Im just so worried about him because I truly love him and want him to be around for a long long time. He’s only 25 and I don’t wanna see him having health issues like I do already at 21. :'(

TL;DR bf made a comment saying he felt like he was actively dying as he has zero energy and I’m worried about his health (he drinks and his a bit on the heavier side) I don’t want him to get liver issues or worse. How do I go about this to try and help. (More indepth details in post, kinda hard to shorten)