Obviously everyone's experience is different, but here's mine:

• initial trip lasted around 36 hours
• First 2 weeks: severe auditory hallucinations almost on a schizophrenia level, mild visual artifacts and "sensory confusion/intermixing" (hearing colours, tasting sounds, etc... If you've done DMT you will understand)
• First 4 months: debilitating flashbacks and DPDR, depth perception and sense of scale completely ruined
• Next 18 months: very mild hallucinations and DPDR on a level of the typical HPPD sufferer, which gradually faded in intensity to a manageable level
• Next 4 years (to present): Intensity of hallucinations settled to a constant level, no longer improving. Unrelated psychotic episode seems to have "merged" with the HPPD such that I now hear people calling my name and whispering to me around 50 times a day. Seemingly permanent?