Helpmrstop22 wrote:
I'm gonna look up the vort again. It was from r' tzadok
I found the following in R' Tzadok's Sefer (machshevos charutz - page lamed dalet in the old print. I'm not sure if it's the one you meant.
"Moshe Rabeinu was afraid that Am yisroel
would not believe that he was sent to redeem them from Mitzrayim, because he was afraid that they were already in the 50th shaar of tumah".
So we can interpret these words of R' Tzadok to mean that the definition of the 50th shaar is where the person is in such a state that he
does not believe that there's any hope left for him.
Like you wrote that Yiush is the lowest point possible.
(so even though he doesn't mention about forbidden relationships, the Actual Vort you were trying to bring out is still there.)