Dear, I think your problem is not about learning, but about what to learn.!!. Choose the degree which is close to your heart. You need a diversion to come out of OCD. You will be normal with your collage, if you are ready to adopt few lifestyle changes.
Next Steps
Do some homework to find out your interest area to decide your choice of degree. OCD is a common phenomenon now a days for everyone due to lack of understanding about need VS want. You can overcome this if you do your own discovery of your obsession.
Health Tips
Practice some meditation techniques to improve concentration. Focus on more physical activities.