I'm sorry this is happening. I've been there before. My advice would be to find a list of symptoms of depression and check off all the ones that you have. You can show it to her and she can see that it's more serious and she might realize it is depression. The counselor might also be able to help if she/he thinks you have depression and you can discuss it with the counselor as well. Then if the counselor believes you have it but your mom doesn't, then she/can talk to your mom. She would probably listen to a professional if she doesn't listen to you.

I hope this helps. Feel free to pm me if you need anything. Good luck with that!