Is it necessary to make a final decision right now? I mean - can you take a pause with some distance? Could you take a vacation for a while, then return to maybe work on things, see how you both are feeling about things?
Your boyfriend's depression and heavy drinking are definitely huge concerns, and that he has spoken of ending his life - very serious, yes, so he needs to seen by professionals, and to keep himself safe. He doesn't need to end his life!
There is happiness.
Hoping for you.