Have I been knitting wrong all these years?

I used to knit that way too. Do you also twist your purl stitches this way? If so, there's no big problem, since all your stitches are twisted. If you purl into the front of the stitch, then you may have a tightening up problem. BTW, this combination is also known as Eastern Combined Knitting, a variation of common knitting. However, yes, you should work into the front leg of your stitches to avoid twisting, and it is the commonly accepted version of knitting in the majority of the world. And, all it takes is to retrain your hands to rid you of the awkward feeling. It is just as awkward to learn to knit Continental style after having knit English style most of your life. Been there too....