I went through/am going through the same thing. I’d have to say it was about 6 weeks to feel significant improvement. But, that said, everyone is different and I had a parasite to eradicate first so that affected the time frame.
Even now (8weeks) I’d say it can come in waves (die-off) just fewer and farther apart.
It is REALLY difficult, especially because it’s not like, oh I have strep throat or something everyone “knows” about and understands. It’s hard dealing with all the crazy mental symptoms and feeling like other people don’t necessarily get it.
I found when I was feeling really anxious/depressed/hopeless, it helped to remember it was probably just die off, and I’d take a hot bath and try to sweat out some toxins. Sometimes even putting on warm clothes after to sweat some more. It helped, also these were times I didn’t feel well enough to exercise, that’s obviously the best way to sweat out the junk.