Denial can be a pretty strong emotion. Your mother may be too scared of the implications of you having depression to accept it. Sometimes parents also feel ashamed of problems that might "look bad" for the family.

Is it possible to get a group session with you, your counsellor and your mother, so that she can understand that you aren't just making this up?
The feeling that a person is "acting depressed" to get out of working is not unusual. I once had a G.P. ask me if I was sure that I wasn't just making up my depression so that I wouldn't have to work. That was a supposedly well educated professional sworn to help people.

Going to school and working at the same time can be difficult for anyone to juggle, let alone someone having problems with depression. If you can stay in school, you will have longer lasting benefits. A degree goes a long way towards your future. There is nothing wrong with jobs that you don't need a degree for, but they are usually temporary and pay less. If you are going to invest in one, school would probably be a better choice.

See if you can convince your mother to either go with you to a session, or see someone who helps relatives of people in crisis.

Sam2