There could be many reasons why you are not getting better. It may be that your doctors and therapists are not as competent as you perceive them to be. From what you wrote, it seems that their treatment plan consists of trying to find the right medication to treat your condition. While medications can help treat depression and many other illnesses, medicine alone usually only provides partial symptom relief. Some people complain that the medicine does not work at all. Good treatment for depression usually involves talk therapy in addition to and sometimes in place of medication.
It could also be that your treatment team has yet to find a medication that works for you. It can often take a long time to find a medication that works effectively for the treatment of depression.
With regard to personality disorders, medicine is generally not an effective treatment. The treatment of personality disorders usually requires some form of talk therapy. There are even empirically proven and specialized treatments available for certain types of personality disorders. Broadly speaking, if you are only being treated for your personality disorders with medication, this might explain why you’re condition is not improving.
Other reasons that you’re not improving may be that you are not following the advice of your treatment team or you have been misdiagnosed. You also say that as of late you’ve been experiencing symptoms of other psychiatric disorders. If you are experiencing these other disorder-related symptoms then it is possible that these symptoms are interfering with the effectiveness of your depression treatment.
Without more information I can only speculate as to why you are not feeling better despite your clear devotion to treatment. I would need very detailed information and an in-depth personal history to provide you with a more informed answer.
Please know that overcoming depression takes time. It also requires your patience as well as competent mental health professionals. You said that you like the mental health professionals who you work with. This is a very good start. You should consider talk therapy if you have not incorporated this into your treatment. Be patient, keep trying and do what is necessary to get better even if that includes seeing a new doctor or therapist. I wish you luck.