New Knitter.Circular Needle Mistake....what do I do?

Hello everyone, I am new to knitting and I love it! I am so anxious to make something and I made a mistake using circular needles. I bought a pair 29 inches long, size 9 US needle, using a multi color acrylic thread, I joined my round I guess, I mean I have a huge circle now, I didn’t realize it until last night and I have spent about 8 hours on it already. I was working on making it a blanket, just doing the garter stitch but now that I realize what I did, I want to make it a scarf because the knitting itself looks almost perfect, I made a few mistakes and have a few bumps but my question is how do I cut the circle and make it a long scarf that I can tie? I am afraid if I cut it it will all unravel, any tips or suggestions please. Thank you

If you try to cut it to make it flat, you’ll end up with a big unravelled mess. You could continue and have it be a doubled scarf–sew up the ends when you’re done.

To make a blanket using circs you don’t join, just knit the rows back and forth like you would on straight needles. The circular needle is for holding more sts than straight ones and keeping it from being heavy as it grows.