Sorry to hear about the drug problems, but how can you be sure they “destroyed” your dopamine neurons? Not all drugs that increase these neurons’ activity kill them. Psychological changes might be a simpler explanation IMHO (but I don’t know you, so that might be far off the mark).
[...] knock out the wanting to do drugs part of their brain...
Sounds draconian. That part isn’t just there for drugs...
Seems like a pretty large leap from certain simple behaviours of rats to the natural-language meaning of “wanting” and “liking”. Far-reaching claims such as this one should have strong evidence. Why not give humans drugs selective for either system and ask them? (Incidentally, at least with the dopamine system, this has been done millions of times ;) The opioids are a bit trickier because activating mu receptors (e.g. by means of opiates) will in turn cause a dopamine surge, too)
(Yes, I should just read the paper for their rationale, but can’t be bothered right now...)