In my first LTR. A short long ago I wrote a post of me thinking that my gf is cheating and deleting messages from someone. I got to see their chat and no, it was nothing. She just responded to some story of a trip he is making and telling him to have fun. Yeah...

I was a little paranoid and even though I'm good at hiding it from her, but every little stupid thing makes me think of her cheating or something like that. It happened more than once and every time I got to find out (mostly me reading her messages) that everything is just fine and she is loyal.

A recent example, she just told me she is going next week to meet a girl friend that I know and sleep at her place. She lives in a shitty city not far from us that has basically no night life. They want to meet and have dinner together as they haven't met for a long time.

For some reason, everytime she tells me something like this all that comes through my head that she is lying in order to cheat. Seriously, she buys me shit, being submissive, that sex is fine, but that thought is really annoying.

I know that I'm really paranoid with no real reason, but what am I missing?

My main question is, what's the right mindset? A friend told me that I should not care and worry, and that I should just let things go, and if one day I find out that she cheats or anything that it's a bye bye. but until then, I should not care. What do you think?