I agree with Jan and GG, ripping back is painful but really the best solution. (You're not going to be happy with steeking and the edges will never look quite right.)
I think this is the pattern
, It looks like garter stitch for the first several rows, is that correct? Did you get garter stitch when you were knitting in the round (alternating knit and purl rounds) or did knitting every round give you stockinette stitch?
It's an adorable blanket and since there's so much work ahead, it's worth getting the initial rows correct. Somhow it always re-knits more quickly than you think and then you're on your way again with a perfect blanket.