Dont swear off flavors just yet.
Most likely its the higher nic. And it might not even be that "18mg" is too high for you now, just that the particular juice, at 18mg, from that company, is too high.
There is too large of a world of flavors out there for you to be swayed by only one bad apple(heh)
Besides, lowering your nicotine level is never a bad thing. Im not of the opinion that its good OR bad, just vape what you like.