It also wouldn't hurt to pick up a few children's books to supplement the grammar books. Once you can read children's books then move on to young adult fiction or short stories, etc. Reading really helps with vocabulary AND it will help you see how the language is actually used outside of a textbook language learning course.
It's hard to say. I only applied to one Masters program (not in the USA) and received full tuition plus living stipend. Had it not been funded, I would not have been able to accept. That being said, I know the Masters programs in the USA offer less funding. When it really comes down to it there are several things I would take into account: if this is the ideal program for you and your interests, whether you think you would receive a better offer if you apply during the next round of admissions, whether the school offers any teaching assistants or project assistantships that you may apply for once you are already admitted, if you still have loans from undergrad and what the repayment schedule would look like once you add on loans (if you plan to take them out) for your Masters program.