My baby shawl is crookered

I have completed my baby shawl after many weeks of knitting. The pattern is a combination of moss and lace stitch. I continued to keep the 160 stitches through out the knit. I did have to undo some knitting but ensured I picked up all the stitches and had 160 before I continued on. Once I cast off I held it up and it’s so crookered. I’m guttered. How could this happen? Is they any way of 'correcting it? And I still have to knit a scallop edge which I’m reluctant to do as I don’t think it will fit nicely on the shawl.
Appreciate any advice.

I would wash it then dry it flat easing it into shape as it dries.