Having a lot more experience than you is easy, doesn't mean that i'm old, genius. More lame-ass conjecture from a rocket scientist. I smell GED. LOL
Concentrate on what you've learned and the mistakes you've made, that way in future you'll make better gains instead of quickly resorting to injections out of desperation.
Obviously you were using insignificant weight on isolations-this time don't make the same mistake. Have some guts, get back in there and build up some serious numbers instead of quitting.
To review some of what you didn't know:
-Curls are not compounds-repeat 25 times quickly. Go heavy.
-Pullovers are one of the very best lat exercises, are not compounds.
-Many top BBs built huge arms primarily through the use of heavy-ass weights on isolations.
-etc