Well, here are some things you should know. First of all, yes, the theater is a tough business to be in. But, that doesn't mean that you cannot succeed. When you're faced with something tough in your life, you will either rise to the challenge, or you will back away and do something else. The theater is a place where you have to confront challenges almost daily, so if you're that type of person, and you really love it, then you'll probably be o.k.
Salaries are very divergent in the theater.
As a side note, getting into television and film, is even more lucrative. So, it's really up to you. If you dedicate yourself to your craft and really work hard at marketing yourself, you can make money doing what you love. Yes, if there is something else you would rather do, then by all means, do it. But if you love performing, and really cannot see yourself doing anything else, then study it with all your heart.