I went into my LBS today, and the bike guy (who I'd talked to on the phone) switched out the stem. He only had a 110 mm adjustable stem on hand, but he wanted me to try it out just so we could get an idea of the size I might need. I could not believe the difference. The 110 mm size is definitely a little too long...but he's going to order a 90 mm for me. And the handling was much more comfortable for me.

Again...thank you everyone for the suggestions.