I have horrible paranoia, which was caused by my ex girlfriend but none the less. Basically I get really paranoid about my girlfriend when she's talking to/about other guys, or when she's with other guys.
I also have anxiety, but I get medicine for it so its not too bad.
Story time; My ex and I had dated 15 months, and she cheated on me for like 6 months and forgeted 4 of my guy friends. So, that's why I'm paranoid, because I don't want to be hurt like that again. But, I'm getting slightly better, I'm relaxing much more, I don't get all defensive about her anymore when people look at her or what have you.