This is one of the problems with telling someone that they have a psychological disorder. People tend to think of them more like a viral or bacterial disease, like AIDS for instance. "I don't have a choice about dying, I have AIDS." But psychological disorders (of this kind) aren't like that. One is a disease of the body, which must be treated with medicine; the other is a disease of the mind, which must be OVERCOME by the mind. Sure, there are drugs that help with a lot of psychological problems, but they're not going to get the job done if the person doesn't work at it as well.
A lot of patients that get diagnosed with certain disorders will say exactly what you've said. "I can't do anything about it, I have XXXXXX" But really, that XXXXXX is just a negative pattern of thinking possibly associated with an excess/lack of a certain chemical in the brain (which is corrected by the prescription given by your doctor). If you choose to tell yourself that you can't do anything then you're exactly right, nothing will get better, and you'll stay this way until you decide that you were wrong and you CAN change things.
My advice would be to just go and make one big change in your life, something that will break the routine, and see where that takes you.