Suicidal but also an asshole

Long story short, I cheated on my ex partner 5 years ago via erp, I didn’t really think of it as cheating at the time but I was and I take full accountability for that, I have not done it since or will I ever do it again, even now we’re over.

They left me, they still live with me and they said they’ll try dating from square one but want to see a lot of change in regards to me showing them appropriate love and I am doing that, but right now we are not together, just living together.

I do not want to be one of those people who are like “woe is me, I cheated and I want to kill myself” but the thought of losing this person forever, the person I wanted to grow old with, I wanted to die with is sending me a bit bonkers.

I’m finding myself making plans to do it almost subconsciously, I’ve been avoiding certain areas for walks, I’ve been trying to focus on them and their grief, which is why I’m posting this to Reddit, it’s no their place to fix this.