So sorry this is happening to you. I was on a high dose of Sertraline many, many years ago. It worked for for about ten years for me but then kind of pooped out. I was switched to Lexapro and when my insurance wouldn't cover it, I was switched again to Celexa. Celexa has worked very well for me for over two decades [knock on wood] but seemed to work only against my depression and not my anxiety, so my doc added Buspirone to the mix and the combination works well for me personally. I hope your doctor finds what is best for you and what will lead to the absolutely best outcome. I find it very scary when a med seems to stop working. My heart goes out to you!