any external source of testosterone will shut down your natural production. and considering the information you gave, id say your already pretty shut down. sust is pretty good at shutting people down as well. id personally say get a SERM and just try to stay natural for a while, maybe a test booster to get some partial effects of a increased test level, but using test just to keep natural levels seems counter intuitive to me. your really risking a lot.
best of luck
eviladams: ya, they came back a little over a month after i quit but my libido was shut down for prolly 2 months after i quit, but when i was on... it was pretty good