BYU is likely my only option
No, its not. You should qualify for financial aid. You may qualify for scholarships. Community college is often free or cheap. You may be able to work your way through. Student loans are subsidized and often make sense (people who get in trouble with student debt tend to be those who invest huge amounts in a bad field). Other universities are similar in price to BYU. How this myth got started that BYU is the only affordable school I'll never know. You DO have options.
Next, quality of life. BYU is not just terrible, but you won't get to enjoy life, either. You can either lie about who you are or not date. You can either lie about who you are or else live alone. You will be at risk of getting kicked out (have fun explaining that one the rest of your life). You will miss out on the best time of your life, socially and intellectually.
Finally, career. BYU is decent in certain areas, average overall. Its not the harvard of the west, no matter what mormons say. That said, what really matters is who recruits there. If you want to work for the SEC, an accounting firm, or in Utah/AZ/Idaho BYU is top notch. Otherwise, other universities are just as good if not better. In retrospect, I consider this the most important criteria when picking a university -- who recruits there, what kind of jobs, what success rate, where do graduates live, etc.
Also, having a BYU diploma, even as an undergrad, simply is not an asset. I have one on my wall right now. It gets a lot more negative comments than positive. Its instant TBM cred with mormons when I was one, but professionally its a liability.
Source: Exmo who went to BYU and other universities.