Impatient Cycling a 90G tank

I am on the 5th week of cycling a 90G tank with one 9" Comet in it. .
Ammonia levels are finally down, but the nitrites and nitrates are
very high, almost impossible to control, I doing 30% to 50% water changes
and siphoning the gravel every day for the last three days. Before that i
was
doing it 3-4 times a week to keep Ammonia down.
I used Biozyme, and Cycle products a couple of weeks ago,
i don't think it did didely $%^#^@&(*
I am gonna lose it very soon if I have to keep doing this day in day out.
I don't understand why the Nitrates are also very high, could the fish be
polluting
the water really bad becasue he is suffering in the high Nitrite levels? I
noticed
more poop even though I am feeding him much less these days.

Is the end near?
How much damage is being done to my fish? (Ammonia burns gills, what does
Nitrite do?)
Are Nitrite spikes generally harder on the fish than Ammonia spikes?
There is alot of green **** in the filter, that stuff is supposed to be grey
or black
when it fully cycles right?

PH 6.5
Ammonia 0.1mg/L
Nitrite approx 1.6mg/L
Nitrate approx 75mg/L
water temp is generally high 70's low 80's.

Should i be checking other water parameters?
thank you in advance... ..Kodiak.