That is a very familiar pain to me. I started programming when I was ten and kept up with it since, but my education was not in programming (although I would take courses as it suited me), so I never had any formal training in data structures or algorithms. I have occasionally found that I had re-invented some known algorithm and wondered just how much difficult I would have been spared if I had known about it in the first place.

Yes, the X73 courses were theory based. Something changed after I graduated and now I think CS 374 is the algorithms course, but I'm not sure.

If you want to start with the fundamentals, CS 173 (Discrete Structures) is required of all undergrad CS majors and is the first of the sequence (usually taken as a freshman/sophomore). The book is available online along with problems/solutions: http://mfleck.cs.illinois.edu/building-blocks/index.html