I think it might be a good idea to put some effort into another girl. I know you don't usually like them right off, but you could start dating someone with potential, at least.

Also, if you're making a nice salary, you should be able to afford stuff like the dinner at the dance competition. Could you really not afford this, or did you just not want to? You're already having money problems with her, and that doesn't sound like you're as into her as you think you are, because if you were, money wouldn't matter.