Afghan is lopsided - suggestions for fixing appreciated

[rra4]

I carefully followed a pattern for an afghan (reproduced below), even though one of the instructions seemed very weird to me (see bolded text). Now that it is finished, it is totally lopsided. Would appreciate any suggestions short of ripping all out and using new pattern.
SIXW 46 x56
This throw is kniw on the diagonal & the seed stitch is used throughout.
Start by casting on and knitting 1 stitch.
On the next row and every "rightside" row, increase on stitch at both ends until the left side measures 46", ending on a wrong side row. CONTINUE INCREASING ONE stitch at the beginning of every other row BUTDECREASE at one stitch at the end of the row. Continue until the right side measures 56", ending on a wrong side row. From this point on, decrease one stitch at both ends every other row until you have one stitch left. Bind off.

[Jan in CA]

The increase on one side and the decrease on the other should make an even section with straight sides which doesn't make sense to me for a square blanket unless it's supposed to be that shape. Can you post a photo to help us understand the issue you are having? There is a link in my signature on how to post photos. If you can't then is there a link to the pattern you can share? Or at least a name? More info is always good.