Before we try to look for a technique or other resources I want to comment on the the you who wrote this email. The person that wrote this is someone with determination, courage, and resilience. You write that, in spite of medicine not working, therapy not working, no feelings, poor focusing, and not-such-good decision making, that you are striving “to fix this.” It is the striver in you, the part of you that is motivated to change that I want to make these recommendations — because that is the part that isn’t giving up or giving in — to the depression.
I would recommend the book The Resilience Factor to begin challenging your own thoughts. Secondly, I would encourage you to take the character strength survey to see what your strengths are and to begin using them. These two resources will help you reduce your negative feelings, and motivate you toward nurturing your own strengths.