Yes, it is possible.

I did not receive treatment for my anxiety disorder until about age 23. Prior to treatment, I struggled thru college with this disorder. I dealt with test and performance anxiety issues. It started with a math course. I became afraid to go to class and then afraid to even go to the building where the class was held. There were days I didn't want to leave my dorm. Although as I said, I had an untreated anxiety disorder. Once I started receiving treatment things improved. I consider it almost a miracle that I received a diploma.