For muscle aches or knots I've used a TENS unit or a foam roller depending on where it's located. You can get a TENS unit for pretty cheap at CVS or Walgreens these days (like $30). Also a good bath with Epsom salts. Sending hugs.

Hives are tricky. I've had several different types of hives or urticaria since being diagnosed with fibromyalgia. I take antihistamines for them regularly and acutely. Muscle knots I use a hot sock (a tube sock filled with rice, tied, and then heated in the microwave for 2 min), or I use a massage gun if i can reach, or a tender point hook. Sometimes my ptsd and anxiety get so bad I break out in hives. I work with an allergist but even he says hives are tricky. Hope this helps.

I know this sounds weird but for my muscle knots I drink pickle juice shots. Pickle juice also helps with muscle cramps. Also warm baths with Epsom salt.

I get hives everyday and they have no clue why. They want to set me up to start getting a monthly dose of some kind of medication for hives. Maybe you can ask your allergist about it. I myself wonder if you can get them from stress? Have you tried Gabapentin? For me it is used for my massive anxiety but it also helps nerve pain and it is nothing like a pain pill or muscle relaxer. If you go to the ER they might give you Toridal which I have been told is like intense advil. I’m allergic lol. Sorry I am not able to help. Best wishes.