Would help if you could tell us what weight of yarn like
Sport, Worsted or what?
Thank you.

Sometimes it helps if you have kept a copy of the yarn wrapper to post a copy on here as it may jog our memory. Also, some of the sites like Ravelry have a board where you can ask to see if anyone has some. Good luck.

This is what it says on the wrapper around the yarn:
a Jo Ann exclusive; Bellezza Collection;100% Wool; 50 grams; Art #07821747 Color #2145 Tesoro Yarn Peach. Is that sufficient? What should I do as a next step? Thanks so much. This is very discouraging, but then I shouldn't have changed my mind, I guess.Barb

Sign up on ravelry.com(it's free) and then use the link below to the search results for your yarn. It shows that 10 people have it in their stash. You might be able to work out a deal with one of them.

Here is a link that might be useful: Tesoro # 2145 yarn at Ravelry