Relationship and how they can suck

For any of you that’ve been in relationships, can you tell me about the best start and the worst end?

Sure. I have only been in one relationship in my life. One real one at least. The majority of the time when I thought I was in a relationship, it wasn’t real - I have a mental health problem. That being said, this is the one that was real. It started by meeting and chatting on OkCupid. From there it went to a phone call, and eventually I drove over to where she lived and visited. From there it gradually went to watching movies on my laptop and going to places like the park and the beach. At first she was kind of excited about me, but that faded. In the very end I became very mentally ill and bothered / harassed her a lot because I didn’t want to let it end. That was the only real start and end, everything else was a hook up or friends and even then I haven’t had sex in over five years.