I have
I have had HPPD twice in my life. In highschool, once I stopped my gross over-indulgence in psychedelics, it went away in one year.
The second time, in early college (where I had been using ridiculous amounts of RC's and classical psychs, most keenly DMT, Mescaline and 2C-E/I), I had HPPD for almost three years. It's a controversial diagnosis and it's truly frustrating when you suffer from it and doctors look at you as though you were still tripping on LSD. I made sure to exercise plenty, revert to a healthier diet and take supplements that promote neurogenesis (I can give you a list if you'd like of what I took).
I'm not sure which was the smoking gun in terms of full-scale recovery, but after a while of abstinence and healthy living, I began to notice the symptoms diminish -
slowly I should add, but they did diminish. If you say you have 6-7 months sober, you are on a
very good start towards being potentially HPPD-free, my friend.
Check out Wikipedia's
page on HPPD, and in-specific, the references section, for more resources to check out regarding it. PM me if you have any questions - I really mean it when I say I suffered with this for many years and am well-familiar with how frustrated and (perhaps) worried you may be feeling right now.
Congratulations, by the way, on your length of time sober :D That's fantastic news!!
~ Vaya