First of all Trib is Tribulus, you can get it from the Health Food stores.

Second of all that cycle is fuked. And whoever told you test was worse than Deca is a fuking idiot. I have said this many times before, and I will say it again, you dont put sh!t into your body until you know EVERYTHING about what you are doing. Your sex drive is down because of the Deca, the Deca shuts off you natural Test production in an instant and if you arent doing some kind of Test with it you end up getting Deca dick. I think you are too far down the track to add Test now, because by the time that kicks in your cycle would normally be over. You could get some Test and run the cycle a while longer I guess. I wouldnt use Sust, try and get some Test E or Test C and do that for eight weeks, do 500mg / week and keep the Deca dose lower than the Test. End the Deca a week before your last Test shot. The other alternative is to cut your losses and end the cycle now and go straight to PCT (you do know about PCT I hope) and restart from scratch in a couple of months. I would choose the second option if I was you.