Unfair?

I go to an all girl school away from home and I'm on a scholarship. I've suffered with depression since I was 11 (will be 18 a week from today) and I told the school nurse and social worker that I was feeling "suicidal" is what they call it but I said like hurting myself. I was informed today that I have been kicked out of the boarding school because they can not "accumulate me and give me the support that I need". I have been at this school for three years and have been feeling this way since the beginning. I didn't tell them anything about how I felt u til this year and the first thing they do is kick me out. Is it just me or is this unfair?