I think that is very typical. you start to feel a bit better and then think i don't really need this. Being dependent on meds or anything means you are giving in, or giving up some of your control. Have you ever figured out what triggered your depression? I know it is a chemical imbalance but usually there is some buried secret you may not even know that triggers the deep dark depression. and do you have a good relationship with your therapist? Do you trust him/her? could you tell them anything?
Do you have a journal? Start one..even on a cheap spiral notebook. it doesn't have to make sense or rhyme or anything start by just whatever word comes in your head write it, and keep going with out thinking...brainstorming so to speak. take it with you to therapy.
have you tried biofeedback, learning coping mechanisms? deep breathing? do you see a psychologist or psychiatrist? If you cry the whole time... before you go in the journal write things you want to discuss... hand it to him/her... i do it all the time.. it is a bit strange but i don't forget what needs to get accomplished and it gives them insight to my thinking process. my depression is not so huge, I have several illnesses and i have some ptsd from some not so fun incidents in the past. so my depression is tempramental so to speak. I hope some of this helps you. I know you really want help, yet you admit to self sabotage with your meds, in your book write everyday 5 things that bring you joy, i don't care if it is a blade of green grass or a grass hopper. slow down simplify and look for the little things that are joyful to you. you can only write one or two things each day that made you feel sorrow. but the deal is once you write the sorrowful thing, mourn it. put one line through it and move on.
hope some of this helps.