It sounds like you just need to recognize the knit and purl stitches, and get more clear on what the stitches you're about to knit look like, and the stitches you're about to purl look like. Then you'll always know where you are, and you won't mess up.
Try watching the top few videos on the Basic Techniques/ More page, which cover the "basic stitches." They talk about how to recognize knit and purl stitches, so you always know where you are.
For k2p2 ribbing, if you have a number of stitches that's divisible by 4, then you always begin the row the same way, starting with k2. The stitches that you knit on the OTHER side, look like purl stitches on THIS side. They should be purled on this row. The videos I mentioned should make this more clear.
Glad you're enjoying the site, and that you've taught yourself to knit! Have fun, and if you have more questions, you know where to come!