I'm in sort of the same boat. Here's what I'm doing: I'm learning Java, for the following reasons.
Java is an object-oriented language and it's somewhat easier than C++. The syntax is so similar to C, I was able to breeze right through learning the syntax.
There are a lot of good books on Java, and what I think is most important is to learn the object-oriented concepts and get a lot of practice writing small programs with them. The second good point is that you can program in Cocoa with Java (there's a simple tutorial that comes with OS X).
I'm finding that I'm having an easier time grasping these concepts with the materials available for Java. I have Apples Objective-C book and the Learning Cocoa book, but I didn't have much luck with them.
Now, after studying Java a little bit, I find that I'm having an easier time understanding them, and am convinced that my understanding of Cocoa and Objective-C will improve if I dip into the documentation, now and then, while I'm studying Java.
I think people in our boat are going to have to sit tight until some more books on Cocoa and Objective-C are available. Fortunately, several are on their way by the end of the year. (Search "Cocoa" at Amazon.com!)
In the meantime, don't beat your head against the wall with this stuff -- get a good book or two and learn Java.