I think my girlfriend is dating me out of pity
I am sorry to hear you are going through that. Why do you believe she's dating you out of pity?
She once rejected me and made me feel like an immature and stupid man and she regretted it. I don't know what happened to her after but we managed to fix it and continued dating each other
Okay, well you shouldn't think she's dating you out of pity. She could well have improved her manners on her own.
I have to admit I'm happy to have her.
It is good to be confident in your relationship and show her that you are a good and strong person.