Pale emperor, you are not alone. I felt similarly when I discovered TTATT. I lost all my friends and a lot of my family. I wasn't prepared for a life without the witnesses, had no idea I needed to be. I went from a feeling of smug superiority and a desire to help save people's lives to being free but mostly alone with and not having all the answers anymore.
At first I spent a huge amount of time researching every doctrine to see if it was something real or not and then I spent a long time being afraid I was wrong and God was going to kill me at armageddon, which I imagined would be starting any time. But, in time I made some new friends, saved my kids from the cult and have a pretty good life going on.
Learning TTATT is really overwhelming but you can and will get through this. Use the board as a helper and you might want to find a local counselor to speak with as well.
Feel free to PM me any time.