"I've lost my confidence in academic endeavors. Can I get it back?"

This question was asked on Ask MetaFilter: querying the hive mind "a community weblog" on March 14, 2007.

I seem to have lost my mojo.

I seem to have lost nearly all my confidence in academics in the last few months. Over that time I've failed many of the classes I've taken, to the point where I expect to fail almost every class I take. Since I wasn't making any progress in school over the Christmas break I decided to get out of school and get a job, with a night class on the side, with the intention of regaining my confidence, but to no avail. The same outcome seems most likely in this class as well. I've often thought that maybe I'm in over my head and that I need to lower my expectations a bit, but I know that I'm capable. My marks in other classes before I had this problem were good to very good, but have eroded over time. My main hurdle in every class I take is that I suffer from ADD and CAPD, among other things, which means it can take me a long time to learn things well, if at all. What can I do to regain my confidence?

The answers may be informative for those also struggling with similar issues. Most importantly, just posting this question and some responses brings more awareness to this issue, which is has been affecting me for about a year. If you have any suggestions or resources, feel free to point them my way.