Wow, $30/hr as a waitress! I used to wait tables and would be lucky to make half that on a really good and very busy day.
Like the previous poster said, wages all depend on where you live. In my area it's starting out at around $16/hour but I've heard in other areas with a higher cost of living, like in NY or CA, it's usually around $25. It's very possible to make more than that as you become more experienced.
If you truly want to be a nurse then you are going to have to make a lot of sacrifices. Live much more modestly and reduce unnecessary bills. If you are worried about finances than I would suggest that you first fill out a FAFSA http://www.fafsa.ed.gov/
and then talk to someone at the financial aid office at the school you want to attend. If you will quit working or will just work part time let them know that at the financial aid office so you will get a much better financial aid package.
Check out the student nurses forum, lots of people there who can tell you how they are currently supporting themselves through school, actually there is a thread on it right now.
Let us know how everything works out and what you decide.