It sounds like you need to go away for the summer and practice. You should contact Professor Ellen Ritscher of North Texas State University about her summer program, and there are a few other summer festivals with lessons like Eastern Music Festival, Brevard Music Center and Interlochen. You can also study privately with someone for an intensive period, two or three lessons a week without going to the country. Also, you should transfer to a school with a harp program or able to offer lessons. I don’t encourage dreaming of a professional career unless you are willing to dedicate yourself and take a lot of risks and chances, because it is still very difficult to do so, but a lot of people play part time, and there are other ways to contribute your music.