Dropped stitches are no fun at all. If you have a local yarn shop, you might stop in for a visit and see if they have a support session available where they can assist you. In the meantime, we recommend attaching a locking stitch marker to the dropped stitch so it doesn't get lost. These YouTube videos may help.
Two Ways to Fix a Dropped Stitch - Knitting Rescue 911 with Olive Knits
https://youtu.be/iwAQaKhIMiw?si=HEbKcxyLoPPDUwoq
Fixing a Dropped Edge Stitch - Knitting Rescue 911 with Olive Knits
https://youtu.be/_q5iZ7I2G8M?si=NmtWn7f1zc7zFqkv
Two Ways to Fix a Dropped Stitch - Knitting Rescue 911 with Olive Knits
https://youtu.be/iwAQaKhIMiw?si=HEbKcxyLoPPDUwoq
Fixing a Dropped Edge Stitch - Knitting Rescue 911 with Olive Knits
https://youtu.be/_q5iZ7I2G8M?si=NmtWn7f1zc7zFqkv
If you don't see that it makes a difference to your sweater, we recommend running a thread through the stitch and weaving it into place on the backside. No one will be the wiser! :)