Congrats on your weight loss!
Last year my husband lost 75 lbs. He's now lighter than before we married 20 years ago. He went to a jeweler and bought a ring guard (about $10 U.S.) to slip under the band and keep it in place. He thought about having the ring resized, but since it has an inscription he didn't want to lose any of the text.
The ring guard isn't the perfect solution, but it's a good stop-gap measure while he makes sure he's not going to gain back the weight. (And we may have the ring resized and re-inscribed for our next anniversary.)
You might want to try a guard or something similar while you decide on a more permanent solution.