While a lot of it does come down to either being "wired" to understand o chem, or not, plenty of people who were not strong in o chem when they started have exited with a solid foundation of knowledge. I guess what I am trying to say is, a lot of people like to talk o chem up as if it is some sort of huge beast, when in reality if you are disciplined and have good study habits, there is very little in the course that can't be overcome.
I think the reason the course washes so many people out is that there are a lot of people who were able to make A's fairly easily in intro level bio and chem classes, only to be taken to task in o chem. O chem requires studying and a good amount reflection outside of the classroom. Very few people can just show up to class, do no outside studying, and expect to make an A.
"Organic Chemistry as a Second Language" by David Klein is an excellent companion book to accompany your text. Klein is good at explaining a lot of the theory behind things.
Don't focus on memorizing the machanisms, focus on understanding what drives the mechanism. Understanding why the mechanism goes the way it does is better than memorizing where the arrows go.
Klein discusses recognizing patterns in certain mechanisms to help you predict products and push the electrons the right way.
A good foundation from general chem about how the orbitals hybridize and what configurations lead to more stable structures is really helpful also.
Klein also has a text book, which is very good. I hate for this to sound like one big advertisement for Klein, but the guy just has great texts. My uni was using Wade's book, and frankly it was a snoozefest. It was just written in a really non-user friendly way.
At any rate, good luck to you.