MDD and OCD (obsessions mild) (no comp)

I've been taking various antidepressants since 3 years. I was first diagnosed with depression when I started thinking about any silly issue for the whole day and getting lost in it and feeling 'we'll die one day anyways' always that kept recurring In mind and I would be lost trying to get that out of my mind. After few Medicines. I started fludac and at 80mg I had a little improvement. But my weight increased a lot.. So out of that concern I requested my doctor to change them.. So since it was my concern about Weight, he made me switch to Sertaline which worsened my mental and body health. I started with IBS. So when I reported this, he started venlafaxine along with it. But this combination didn't help too.. Then I told the doctor that I felt much . So he told me that I gotta compromise with weight issue Now he introduces fludac 20 and increasing dosage step wise and simultaneously decreasing sertaline step wise. am I in the right track?