Depression/Motivation problem?

I can't make good grades in school. I have depression which I have recently started taking welbutrin for. I'm in 11th grade and doing middle college (dual enrollment) at the local community college. I would like to transfer to a 4 year school and then go to law school but last semester I made straight c's. I do well on standardized tests in 7th grade I made a 21 on the ACT, and was projected to score in the mid 30's on the ACT when I took the PACT. I made good grades throughout elementary school and in 7th grade since then they have steadily gotten worse I failed courses at my old school. I skip an alarming number of classes and do no work outside of school. I didn't attend a single class one day a while ago and just sat in my car thinking about suicide not seriously kinda half heartedly. Now I am medicated and don't feel down so much but still I don't have any motivation to do anything. I'm not out if shape I hang, out with friends a lot. at home I play video games some and other stuff sometimes I just do nothing the other day I just layed around on the hardwood floor for no reason just doing nothing. Sometimes I feel like I just say I want to be a lawyer because my parents expect me to grow up and do some standard middle to upper class job just like them. I really like cars and would really just like to tune performance cars and be an auto mechanic or drive for a rally team but I don't tell people that because I do want to have money I just am so bored by school and can't make myself try even though I want to. I don't know what to do. I may just seem lazy, but when I had a job I worked hard and seemed to kind of be climbing the corporate ladder. I'm going to start working soon (this time for my parents). I don't know I kinda want to drop out and be poor. Sometimes that sounds like a better option than school. Any advice is appreciated.