Bro, bad idea starting with test so young. Your body is still producing so much test you would be better off starting with a low dose of Dbol for your first cycle. Trust me if your diet is on point, your calories are high enough and your lifts are heavy you will grow like a weed on a handful of Dbol a week. After a few cycles under your belt and a good diet gradually move into test cycles, then start stacking test with other things. You blew up with the 500mg but you could of done that without such a heavy cycle. I recommend depending on how long ago that was, go to your doc and get your blood work done, check your free test, total test, IGF-1 levels, lipids panel ect. See if your levels are normal and where they should be, if so ease into the AAS world. Your only 20 and you got a lot of years to pin your body and trust me you want to still respond to stuff when your 30 and not have your test completely shut off.
I would ask before even recommending a second cycle, what your diet like? Pro/Carb/Fat % split, Whats your goals? Cutting, bulking, strength?
Granted no one wants to do the hard work, and you prolly wont listen to this b/c you might be one of those guys who thinks you know everything but if you care about your body its worth a shot. Trust me we dont say this stuff to piss you off, its just b/c a lot of us have done this before and now to put on the weight we have to spend A LOT for the same results.