I find myself making repetitive mistakes typing keywords and sentences in my code comments. I notice its getting worse since my fingers just keep "practicing" incorrect words.
Is there any solution to this? Like a typing tutor designed to help correct repetitive mistakes?
Maybe a book? Mastering Computer Typing: A Painless Course for Beginners and Professionals I hadn't read that, but in amazon has good reviews
The only way to correct this is to retrain your muscle memory. If it's important enough to take the time, the only way to retrain muscle memory is repetition.
For example, I tend to spell the word "the" as "teh" because of the same scenario you're asking about. To retrain the memory I would just spell the word over and over, starting slowly, striving for 100% accuracy, and increasing the speed. It's the same technique I use to get better at Guitar Hero.
Try a different keyboard layout. That way you start from scratch and completely retrain your fingers. Done properly you should be able to type just as fast as you could with qwerty in a few weeks. For example Dvorak.
</shameless promotion of dvorak>