I continue to try and reach out to an old friend, an old flame as they say, I don't know what to do about this?

I don’t know if I should stop, or keep trying. This person has given me so many chances, and I keep messing up. I can’t seem to just realize that it’s totally over with them. I guess you can assume that I haven’t been very, well. I am well, now, significantly so. My old friends are coming back into my life, but it’s this one person I can’t let go. Guess I answered my own question, by continuing to state I should let it go, but maybe I can get some new perspective from here. I fear this may be one of those, “oh not another one of these questions” but I thought I’d ask, thanks