I'm 4 months in now and my experience has been this: foggy brain, insomnia, anxiety, lack of energy, irritability and fatigue all coming and going at seemingly random times. As time goes on the severity of these symptoms lessens and the feel good periods lengthen. After 3 months I felt significantly better, even better than that after 4. I too am looking forward to the 6 month period as I am not where I want to be. But hang in there, if I'm starting to feel better anybody can.
Also, I know what you mean, I've asked people when they started feeling better and got answers like "10 days" or "2 weeks" I would get scared that this was as good as it got. hang in there, it will get better.