Welcome to KH!
Maybe you missed knitting a couple of stitches? That long yarn loop looks like it was carried over the sts but not pulled through them. You may have to rip out a couple of rows and then tink back the last row, putting the needle into a stitch as you pull the yarn out of the stitch. But..
Before that however, you could try knitting over to the column with one of the missed sts, dropping the yarn off the needle to the long loop, fixing the missed stitch and then laddering up again. If that works, try it with the next stitch.
Here's a video for laddering up garter stitch.
If this doesn't work, you'll be no worse off. You'll just have to rip back and tink to repeat the problem row. Good luck with this.!