Ah, man, your pain is oozing out of the screen. That's a rough place to be in.
I'll second LovingRadiance in saying that it's best to first take care of one's own issues before trying to work out relationship issues. As an ex-wife once said to me--"I figured out that it had nothing to do with you; I wasn't dealing well with my personal issues and took it out on you." Personal issues are the cause of as many (or more) divorces than relationship issues, it appears, as the personal issues create relationship issues where there otherwise wouldn't be any.
One of the first steps is to actually identify those issues. From what you've posted, I can see some.
"...would make me few like less then I should be to her." Um, what, exactly, do you think you should be to her? Why do you think you should be that? Where did you get that expectation?
I'm guessing that you think your relationship should be all she needs (or something similar) and if she needs another, then you're deficient in some fashion. Why would you think that? Do you think she should abandon her family and friends because she's with you? I mean, if you're supposed to be everything she needs, why would she need family or friends? Can you grasp the notion that people have all sorts of needs and that it takes a bunch of other people to meet them all?
If she wants a girlfriend, then she's bi--and there's no way you can substitute for a woman. Sorry. She's going to have to have a woman to fulfill that need.
"She makes me feel special...but now she wants to be with someone else too. It hurts."
Would you not still feel special because you're dating her? Does it hurt that she has friends and family with whom she spends time? Are you not special because she spends time with and cares for those people? Are you afraid she won't spend time with you?
"It makes me feel like I'm not enough for her to be happy." Why would you think her happiness resides in you? Why would you think she's not happy because there are other people in her life? Do you think she's not happy with you because she has friends and family in her life?
And you're not enough what? Have you asked her if you're enough of what she wants from a boyfriend? Are you expecting to be more than a boyfriend? Trying to be her father, too?
Have you asked her what she expects of you? If you're providing what she expects of a boyfriend, what's the problem? Why are you trying to take over other peoples' spaces in her life?
I suspect that you're providing her with what she expects from you. Any fretting over anything other than that is your issue--and you're correct in assuming that it could cause problems for the relationship.