My girl gets pretty bad heat cramps. I took her to the vet a few heat cycles back and they literally told me "it's just heat cramps, there's not much we can do." I'm not a vet myself so I'm not going to recommend CBD oil or whatever else. Normally with my girl her heat cramps are bad for the first 3 days of heat, and then they normally go away. For those three days I normally snuggle and cuddle with her. She doesn't want to leave my side because I'm a source of comfort for her. If nothing else, I'd recommend giving your girl extra attention. Make her feel extra loved and cared for in this confusing time.