Hi people

I am bipolar. I currently take quetiapine and lithium an have been stable for ages. I work full time. I have also been taking codiene for over ten years. I have tried to stop it but feel awful when I do. It seems to work on depression far better than antidepressants ever did and without the hypothymia. I don't take huge amounts about 60mg a day sometimes a bit more. I know I should stop but I can't. Any one else in same boat?