If you feel that you have been unfairly treated, demand justice.
We are not born with a fixed amount of intelligence. The human brain can grow with each new mistake that we make and each new discovery; and those neurological links are made stronger each time you practise a skill or talent to a level of mastery. You are doing yourself an injustice if you believe that you can't learn. Your brain is an amazing organ that can grow and change. The only things that you need to make this happen are purpose, persistence, practise and opportunity.
If you ignore the signs and symptoms of stress, you'll never find the root cause. If you don't find the cause, you can't deal with problem at its core.