<human>: My SO and I have been together for just over a year now, and so far everything has been great. She's really an amazing person, and we get along incredibly well.

However, I suffer from occasional feelings of paranoia that she'll cheat on me. My last long-term relationship ended when I found out that my (then) girlfriend had been having an emotional affair with a good friend of mine for over 5 months. I believe that has created some insecurities that have carried over into this relationship.

 For example, she is currently at a State Tournament with her Debate team, in which she's spending the weekend (plus Monday and already Friday) in a hotel with  the other team members. The tournament and the dance that follows it is notorious for a lot of partying and sleeping around. She has never shown any sign of cheating on me or any will to do so, and rationally I know she never will. Nevertheless, at times like these I am constantly finding myself thinking automatic thoughts of "what if she is cheating on me?" How can I end these thoughts and rid of my insecurity?

Can you give me the gist of the text in a nutshell?
<bot>: I occasionally get paranoid that my girlfriend will cheat on me, even though I rationally know she won't. How can I get rid of my insecurity and stop worrying?