I can’t tell you if you’re “straight up bisexual” because I’m not you. I’m not in your head. I’m not feeling what you’re feeling. But I do know that the confusion and pain your describe is real. I know that sexuality is fluid and that bisexuality absolutely exists and if you feel in your heart that you are drawn to both men and women, then that isn’t something to shy away from or feel ashamed of; that’s something to embrace because that’s who you are. That’s who you are, and there’s nothing wrong with it.
I don’t know what it’s like to be bisexual, but I know what it’s like to feel alone, and I know what it’s like to feel confused, and I even know what it’s like to feel as though you’re letting down the people who love and care for you. But the one thing that will help you feel less of those things will be connecting with other people who are in the same boat as you. Even though you live in Texas and your school doesn’t have an LGBT group, you can connect with people online, speak with people at LGBT hotlines, or find bisexual organizations in Texas that you might be able to connect with/drive to. In addition, you may find these links to be helpful as well. You may even decide, after some more soul-searching, that living in an area where you feel more accepted and embraced is crucial to your well-being, and thank God, there are plenty of those places in this country. You don’t even have to leave Texas! Austin, for example, is a very progressive city with numerous LGBT organizations.
Since you are in school, I would also suggest taking advantage of whatever counseling services are available to you on campus. You may not have a specific LGBT group you can connect with, but talking to a professional about the process of coming out — first to yourself, and then to your friends and family down the line — will be instrumental in helping you feel less alone. Your school’s mental health/wellness program will likely even have LGBT-specific resources you haven’t discovered on your own. I assure you you are not the first college student to grapple with her sexuality. Even in Texas.
You aren’t alone, my dear. There isn’t anything wrong with you. You are perfectly normal and perfectly wonderful no matter whom you find yourself attracted to. And in the words of Dan Savage, it gets better. It gets a lot better, and accepting who you are is only the first step in getting there.