hmmmm , im am on zoloft myself at 100mg a day, it really didnt kill my sex drive or erectile issues but it did not help it.
I also smoke aswell, i know that doesnt make things better.  I was on seroquel for a short peroid of time and it basically made me wierd as hell at night so i dropped it(this was a few years back).
I would decide how important these drugs are for you, i know i must be on zoloft a min of 50mg a day.  Maybe you could try dumping the seroquel and lowering the other doses??? I suggest doing this one at a time with some time in between each change.  Also maybe throw some arginine in your daily routine to try to keep the blood flowing, try to keep a proper diet to, i would stay on the sustanon I am not a believer of running any hcg while cruising or blasting test, i just scientifically do not see the point.  Sexual sides are very very mental to i can be rock hard packin a extra inch or two with one chick then have a semi errection with another.  Hope this helps a little