People grow apart sometimes, but if he loved you before then there’s a very good chance he still cares about you. Maybe he’s just unsure of how to show that.
I think the way to stop feeling guilty is to stop wanting to die, which is really difficult and may seem impossible. But the guilt is something that can keep you from acting on any suicidal thoughts beforehand. Keeping in mind that there’s someone out there who makes you happy and who you make happy in return, and knowing how killing yourself would make them feel can help you to reconsider. I don’t know your situation or anything that could make this advice a bit more personal, but I think the best thing would be to make yourself truly happy first.
Cooking slightly complicated recipes while singing. It helps to keep my mind on other things, plus I get some really good food out of it in the end. By the end, I’ve usually worked out my frustrations and have calmed down enough to approach my mood rationally.