Losing someone to suicide sucks. I’m willing to bet there is at least one person in your life who would be sad (or perhaps devastated) if you suddenly died. Even if it means continuing on while unhappy, don’t put that person through such an ordeal.
Depression is a temporary condition. It feels like it’ll last forever and that life can never go back to the way it was, but that’s not true. It might change you, and that change might be for the worse, but you can escape it. You can. It’s hard, but it’ll be worth once you’re on the other side.
Start by seeking professional help. There are affordable (and, depending on your area, perhaps free) options out there. Then, change how your mind thinks. Don’t let those thoughts rule you. Fight them! You can do it!
Call me crazy, but typically when someone asks for reasons to not kill themselves, depression is involved. Maybe OP was just starting conversation, but given the question and the increasing rate of people struggling with depression, I thought I’d offer my thoughts. I don’t believe this answer was condescending.