Mine’s super long too, and you can get extra-long ones! I posted on /r/longhair looking for them a while ago because I’ve had the same problem. The bottoms of my hair always stick out of tee shirts, and I’ve even tried using my microfiber hot yoga towel, but it’s too narrow too.

I have an Aquis one that I got at Target, and it’s actually elasticated so it holds far more hair than it looks like it should—I actually have a few extra inches, which is amazing. There are also a bunch for cheap on Amazon, sometimes in multi-packs. Example. Just measure how long your hair is (when flipped, because your skull will eat some of the length) and check they will fit.