Stretched wool while knitting

I am working on a sweater that is seemless; using a circular needle; it has gained 10 inches and I am not sure if this is typical for all or just me!
What is to be done? Must I start over? Will this stretching go away with blocking and finishing?
Thanks for any help!

Were you following the pattern for the right CO number? Are you using the right size needles and yarn for gauge? A CO for just about any needles and yarn is going to be about 80% of the full width; as you knit it stretches out to the correct size. So if you measured your CO to be the size you wanted, yeah, it’s going to get bigger after you’ve knit a few inches.

I am so new to knitting, that I don’t even know what CO is! I am nearing the end of the body length of the sweater and found that the wool had stretched; the pattern is general and one must find the needle and wool one likes for the person the sweater will fit! The suggestion was to measure that person’s favorite sweater and go with that for size.
Will steaming to block reduce to normal, or should I unravel?

A CO is Cast On. Steaming won’t make a sweater that much smaller. I’d suggest you rip it out and make a smaller size.

Thanks! I was afraid you would say that; I will knuckle under and do it right!
I have gotten in the habit of picking up my knitting whenever I sit down, so there is no purpose to doing it wrong!
I am still smiling and loving it!