Hey man your not psycho, your just insecure and clingy. You need to be confident in yourself and stop overthinking it.
I can smell your insecurity just from reading your post. If she talks or hangs with another dude that is perfectly normal. For example if you started talking to another girl and your girlfriend started getting jealous, that is a huge turn off.
If you truly confident in yourself as a individual, this shouldn't be an issue for you.
Now let's say you were right to be insecure/jealous and she cheated on you. Then so what, just move on