Ouch! That's a very large row. Unfortunately, the best thing to do is to undo what you've done in this row, cut the yarn and cut out the knot, and then start the row over and join the yarn again. You could keep knitting, but then you run the risk of the knot coming undone and your beautiful piece unraveling, which of course you don't want. lol.
In the long run, it will be better to fix it now than have to fix it later. Good luck!