Take heart. It will not last. I observe two things as an outsider. First, you are going through a major life transition. Transitions have always been bumpy rides for me. There is the excitement of a new life. Your body and brain are used to your old life. The best times of my life started in despair and angst. My first days of college and law school, a new apartment, work, etc. all started with wondering whether I would have a heart attack from the fear. Within a short time, however, I felt better than ever. Everything precious in my life started with anxiety.
The Witness religion is not a casual affair. It is the central event of your life. Why do you think we have so many meetings and field service? It reinforces the message that we are incomplete. We need the GB and the elders. If we are busy with Witness life, we have little time for exposure to the real world. I don't know if Steve Hassan books are that good. The phenomena of cults is widely reported. Try a google search to find out what happened to your brain. Leaving is not easy for most people. It can be very hard. Give yourself credit that at least you have now and the future.
Moving, losing relationships and a religion are major stressors. You may have major depression which is biological. If you do, you need appropriate treatment. The Witness mindset may reappear here. Self reliance is not enough to treat it. Seeing a doctor to be screened is a good step. The sooner you are evaluated, the sooner you may get relief.
You should commend yourself for posting here. I believe if you read posts here many here faced similar situations. The former Bethelites come to mind. They were so involved with t he Witnesses that they worked for almost no wages at Bethel to serve Jehovah. Terry, another member, went to prison during the Viet Nam War. They paid heavy prices for believing in Witness doctrine. Everyone has a different experience but I do believe that most don't jump "Yipee. Let me leave and have a normal life." It takes time. I left very young. There are parts of the Witness life that haunt me even now. It is a process. What people report is that once they complete the transition, they are much happier. Many members decide to finish education that was delayed. New friendships are formed. It is not an overnight process.
There is a saying about moving. You take your problems with you. I do observe as I move through communities, though, that some are more hospitable to me than others.