Thanks so much for your replies everyone! I just wanted to update and let you know that my husband actually taught me how to "fix" the pain.
He is a chiropractor, and of course knows a ton about the human body. He taught me how to dig deep, right at the end of my left rib cage and push down and in. While pushing, he made me take several deeps breaths. Essentially, he moved my stomach down so the band wasn't poking in my diaphragm anymore.
Ahhhhhhh, relief. I love my husband!