Did you jar up the BHO you sprinkled terps on?
Making Diamonds is simply crystallization out of an appropriate solvent (or solvent mixture). If following Only The Strong sauce tek that solvent mixture is mostly terpenes by the time things really start happening.
I believe you could do better than “sugared like crazy” if you added approx twice the solvent you added last time, then jarred and waited.
Yes, terpenes qualify has hydrocarbons, being built of only hydrogen and carbon atoms (no Oregon: CO2 is not a hydrocarbon). terpenoids contain atoms other than H & C.
yes, getting the extract “wet” is what allows the THCa molecules to move around and find their buddies (and crystallize). Too much solvent, and there isn’t enough motivation to “buddy up”. Too little solvent, and the molecules can’t move freely, so no or only tiny crystals.
yes, that “twice as much as last time” is a wild guess. I don’t know what you did, what your starting material looked like, or what sort of sugar you’re looking at. I don’t even know if you jarred it. 
If you didn’t, then you may not need to add more solvent, just slow the evaporation down (by jarring).
From the reading I’ve done, starting with sugared material might be problematic. in that you have essentially seeded the reaction. so you might just get sugar again unless you are meticulous about dissolving every last bit. filtering it might help, but I’m not sure you have the tooling for that (syringe filter would be my suggstion).