Hello, I'm Norman. Are you ready to chat?
There are a few possibilities, and one of them is that your anti-depressant needs to be changed. Given the dose that you are already on it seems unlikely that your prescriber will want to increase it.
From what you have said, it certainly looks as if your depression is worsening.
can my body become immune to the depressants?
Not immine as such, but perhaps resistant might be a better word. I think you should discuss this with your Doc, and see if he is willing to reievaluate your medication. Furthermore meds are useful at helping to control symptoms, but they do not get down to root causes. The combination of meds and psychotherapy is a much superior approach.
Have you had any psychotherapy?