For introductory math, I've enjoyed the Art of Problem Solving series. I too prefer the slow and thorough method of study, and these books are really comprehensive.

For study motivation, try the Akrasia Tactics thread, as well as these posts.

For myself, I've found that the best study motivator is to attend a class on the subject, even if that means paying for it. In fact, paying for it is an extra motivator to do the necessary work.

I'm actually in a very similar situation to you. Several of the links above were provided by Jonah Sinick over at Cognito Mentoring. I'm in the middle of an email conversation with him and he's been very helpful.