Hiya,
Yea, Orgo is make or break at my U. Some call it "pre-business".
Anyway, as TA, the biggest mistake I see people try to make is to memorize their way through Orgo. Unless you have PERFECT photographic memory, this will not work.
I was VERY fortunate to have a prof that chucked the book, and taught us the basic tools for Orgo, right from the start (electron pushing, etc). You have to know WHY things do what they do, rather than to memorize. It makes everything MUCH easier.
Organic Chemistry I (and II) as a Second Language' by Klein are both excellent, and I recommend them to all of my students. But if you are more than halfway in at this point, they will be of limited usefullness.
That said, a W looks better than an F, so I'd consider that as an option.
Oldie
PS. When all else fails "steric hinderance" works as an answer more than half the time