Nursing courses are different than prerequiste courses. Ask your classmates to help form a study group. Buy or borrow a NCELX review book. Talk to your teachers, review the tests, see what you missed. You're smart enough to get this far, keep plugging.
If the hospital is having an open house, that generally means they need nurses. Definitely take your resume, take a unit tour if they offer one. Okay to make contact with nurse manager as well, that way they can put a face with a resume. Sometimes resumes and applications never seem to get past the HR folks.