My parents don't believe in depression...?

Are you 18+...?? You say you are home for the summer. Find a therapist near you. Perhaps call the counselor you were seeing and ask for some istance is finding one near you. You are not going to convince your mom, go and find someone. Many people do not realize what true depression is. Do an internet search on psychologist in xxxxx (your city)... apa.org website has a "search for therapists near you" function.....find someone....good luck! (psychologist)