Is there anyway possible for me to up my GPA in a short amount of time?

Hi, My name is Amanda Ibarra, I have always had issues with my grades since I was young and it was normal for me to change schools many times over, running from my grades. When I was in 11th grade I finally broke down and dropped out of school and was planning on receiving my GED, however that proved to be a mistake and my mother begged me to return to school, so I did. I am attending an ALC(Alternative Learning Center) type school now in New Ulm Mn, and I have decided I want to attend a University to study psychology myself, however I am stuck with an issue, I have a very low GPA and I only have one more semester of high school to attend until I graduate, so my question is; Is there anyway possible for me to up my GPA in a short amount of time, and if not would it be a better idea to attend a 2 yr community college for my generals before attending a university having them transfer my transcript from a college to a University, then attend that university for my doctorate degree in psychology.