Ive had costochronditis in the past, normally on the left side of my chest (which caused freak out mode to kick in), but lately, last night coincidently, it enveloped my whole chest and back. Mine was very uncomfortable but it wasnt a sharp pain as you experienced, more of the burning sensation. Ive had heart monitor and heart ultrasound to rule out anything and my heart is healthy.
What I do, and what I’ve done, is try to stretch a bit, massage it if I can, put on a heating pad, and take Tylenol. I take extra magnesium glycinate but whether it helps specifically I don’t know. It does keep the leg cramps away.

I contribute EVERYTHING to fibromyalgia but I usually have it checked out if I find it worry some.