I am literally in the same boat and situation as you. I have received 3 rejections, 1 interview offer, and am waiting to hear from 3 more schools. The GRE is the only thing that I don't believe is stellar on my application. Besides that, I have about 2 years of crisis counseling experience, have a history of community service at hospitals, rehab/care centers, etc. I have volunteered with an organization who supports individuals with metabolic disorders for 9 years. I also have interviewed and shadowed multiple GCs, and have volunteered in their clinic at one of the best cancer centers in California. Receiving rejections has been hard, I truly thought that I would get many interviews based on my grades and experience. At first, I was like how can my GRE score bring everything down? I have been told that its not everything, but who knows what they are exactly looking for. There are sooooo many different components of the application that they are looking at, as you know!
A GC told me that every program is unique and many qualified individuals get turned away each year. Each year they are looking for something different. I have interviewed about three GCs that didn't get in the first or even second time and they are phenomenal GCs now. My best advice to you, is to stay strong and don't feel defeated. You have an interview and thats amazing! Think about it, you passed many different admission screening processes to get that interview. They know you are qualified to be a GC on paper, now its time to meet you and see if you are a fit for the program, as well as, the program being a fit for you! So prepare well for your interview. It only takes one interview to get in. I have friends who applied to like 13 grad programs, only got one interview, and were accepted! I totally understand how you are feeling, If you ever want to talk feel free to message me. I hope you have an awesome day!