I don't know how your reverse function works, but on my machine (Husqvarna Viking) when you press and hold the reverse button it will stitch in reverse for as many stitches as you want as long as you hold it. However if you press the reverse button twice and let go, it will sew in reverse until you press it again. Is there a chance your machine works like this and you have put it in reverse? If it is a computerized machine try turning it off and back on. Good Luck. Hopefully someone else may have a suggestion.

Recently my foot peddle got wet. When I turned on the machine, it immediately started sewing in reverse, non-stop, all by itself, as if a gremlin was operating it. I panicked, let the peddle dry for days before I had nerve enough to try again, but when I turned it on, the machine was fine. So, perhaps moisture or high humidity is the culprit.

BTW, my machine, a 30+ year-old electronic Singer, is similar to Chickadee's, except that if you press the reverse button WHILE you are stitching forward, it goes to reverse while you hold the button and goes forward again when you stop. However, if you press the button BEFORE you begin stitching, it stitches in reverse until you stop and press again. Good luck, kenglish.