Relationship troubles.....(read detailed description please)?

my girlfriend Megan and i have been dating now for a month and a bit now and our everyday life ges harder and harder. She isn't happy with herself, she thinks everyone is better than she is and she takes it out on me. She doesn't want to do anything like watch movies because of girls, or anything we do it ends up with other girls, i'm a nice guy and i would never cheat on anyone. She doesn't want me to hang out with friends because she thinks they will be a bad influence, and she worries about everything all the time. I'm 19 years old and she is 18. I dont have any fun anymore. We have had so many good memories, but i think more bad ones, i like her family alot but it almost seems no one has any idea about our struggles, i would like to hang out with friends and know that we trust each other but it never is that way with her...... are we just 2 totally different people? i need help, i dont want to live this way, and i dont know what to do..... can someone give me advice?