Girlfriend over analyzes every detail

Hi, really need an unbiased opinion! im with my GF for 9 months now and its been brilliant. every second we spend together has been brilliant and i honestly see her as the one.... shes the first GF ive had who i saw a definite future with. the feeling is mutual... she's told me that im perfect for her, that im the nicest person shes ever met and that she sees a long and happy future together. so all is going really well..... the problem is, unfortunately my GF has had a few tough situations from her past; she had a tough father who was tough on her mother, he accepted nothing but first and made her and her siblings extremely driven. her mother has also passed away adding to the situation and as well as that, her sister has been unlucky enough to develop a mental illness, other shitty stuff has happened to her niece so theres been a lot of crap basically mentally weighting her down. this she feels has resulted in her not being able to give herself fully into the relationship. although she loves me more than anything, shes afraid to make a mistake and the last thing she wants is to be responsible for bringing more crap into her families lives. she also feels that she has turned into her dad sometimes by being hard on me about tiny things that annoy her, little traits like being figity or crossing my legs a certain way.... as i said, all little things.... also there have been one or two times where, when we were out, guys would be trying to chat her up or whatever and when she's say shes with me, they'd say "youre with HIM???" implying that she can do much better, and this really upsets her. it upsets me too because i know that theyre just being assholes but she gets worried and thinks that theres something shes missing about me.... and there isnt, ive been completely open and honest and told her literally everything there is to know about me.... so its frustrating for me too because i feel like theres nothing i can do to help her. i suppose all this has led her to be a touch insecure.... again the idea of making a mistake is what shes really worried about. shes told me millions of times that she loves me more than anything, that the feeling of being together is amazing and nothing shes ever experienced before and she thinks im the best thing thats ever happened to her and that her gut is telling her that im a fantastic person and that shes really lucky to be with me. after last weekend, she has decided to seek councilling in order to move on from the emotional baggage she feels thats holding her back in our relationship. im just worried that im going to lose her. i know we're perfect for eachother, and things are going so so well. and at the end of the day we're only 9 months in so all this is very serious so soon.... as ive been telling her, just enjoy the now and when real problems come up that we'll get through them together. i just want to know what people think of the situation? thanks John