We broke up after she cheated on me. This was her second cheat. I quit talking to her and haven't spoken to her since 2 years ago. She uses mutual friends as conduits to say hi to me every now and then. She married the guy but has told my closest friends she misses me. I didn't start thinking about her everyday up until October 2013. I'm having thoughts of breaking my silence but I know we'll start seeing each other again. Can somebody tell me why I'm thinking about her a lot? Can lonliness attribute to it?

THen you are having issues... and need to be under the treatment of a medical professional... perhaps a psychologist. WHat you have is an obsession... an unhealthy one. Most people would have moved on in their lives long before now.

Yes it could be lonliness. Keep your mind active, exercise, get involved in groups or clubs, etc. If you could be objective you would know that wanting or accepting her back would be settling for somoeone not worthy of you. She cheated. Twice. You can and will do better.

Cheaters want and need the excitement of cheating.

https://www.askmehelpdesk.com/relationships/we-like-each-other-but-shes-long-term-relationship-788727.html

We are talking about the same girl aren't we? After all she has done, and all she has put you through, the old wounds are still fresh because she keeps them that way. You see very little is needed to refresh old memories, and feelings and misery.

Happens to us all and the only thing to strive for is build a life that you enjoy to put those feelings behind you and be happy despite the reminders of a bad experience. All my exes still haunt me from time to time, both the good and the bad, and its been 40 years or more. Old memories are temporary after you have a great life for yourself. But for now you are just dwelling on reminders and triggers, made worse by your circumstances. You really do need to get out and build NEW memories and experiences, with people, places, and things you enjoy and look forward to.

I agree, if same girl, the only thoughts would be anger.

You need to get out and date, have a social life and not be lonely.