Seven years is a while to have had AF. I started NB almost as soon as I crashed and I'm still working on it a year and a half later. So...maybe you will take some time.
As Onwards said, addressing other stressors might be a good idea. Just go down through the list like she said. I've recently discovered a parasite infection to be a huge stressor and am addressing that. I have gotten somewhat better even now, but I can tell this infection needs to go before I can progress much farther with NB.
Also, something I remembered, I was in three lows for the first year of NB then slipped into four lows. there was a profound difference in my energy when the change occurred. All the sudden I felt back to square one. This is okay and is normal since your body is resting. Take the signal your body is giving you and just rest and take care of yourself. Just ride the wave. I did this and started feeling better after about two or three months. I still have plenty of fatigued days now, but not like before, not as many. You may be just on the verge of, or just entering four lows.
Copper dumping could make you tired too. My husband has copper toxicity and fatigue along with many other odd things has been with him while he's dumping it.
All the best to you:)I hope you can find what works for you!