You really think such an intense experience as DP/DR could be caused by SINUS problems?
We're dealing with something that has an unknown mechanism so there's not much point to come with any preconceived notions about what I or anyone else thinks DP is caused by. If she says she got rid of DP by temporarily fixing her sinus problem and fixing it permanently gets rid of it completely that's good enough for me, especially if it does the same for me as well.
If I can get rid of DP by clearing my sinuses I care very little about the academic question of what else may have combined with the sinus issue to give me DP as long as it's gone.
For all I know a swollen sinus presses on the pituitary gland (or it's the infection itself that raises cortisol) which in turn causes a hormone/neurotransmitter problem that manifest itself as DP(for ex see
http://www.ajronline.org/doi/full/10.2214/ajr.175.6.1751570 where it details a sinus infection acting similarly as a pituitary tumor).
And symptoms of a pituitary tumor include:
Various psychiatric manifestations have been associated with pituitary disorders including pituitary adenomas. Psychiatric symptoms such as depression, anxiety
[36] apathy, emotional instability, easy irritability and hostility have been noted.
[37]
One study, which compared the prevalence of microadenomas in those dying from suicide and those who died from other causes, suggests that pituitary adenomas belong to suicide risk factors.
[13]
There's a thread here with a bunch of people taking HPA axis supplements going DP free in 2 weeks. The gland extracts they tried had hormones included. The ones I got were hormone free. Maybe that's why it didnt work for me. Next step is to try to get that exact brand.