That's an awful experience. *hugs*
You are not the first to post something like that about a GP, sadly I suspect you won't be the last.
In my experience GPs seem only geared up to deal with situational anxiety and depression, even helpful GPs just don't get long term MH issues. Many seem to think it is just about pulling yourself together because they can't see an immediate cause. I suspect that is something to do with their training. I had one consultation where the Dr sympathised with the lack of mental health resources in the NHS by saying it is a shame all resources are needed to deal with serious illness.
She was mortified she had said it but it was indicative of an underlying attitude.
I know it is hard to see right now but you are not responsible for your Dr's attitude, opinions and unprofessional behaviour.
You can change to another GP surgery in the area without giving any reason, you just find a local doctor accepting patients and they will sort the transfer for you. I did it and am pleased with the result.