Costochondritis is very painful and that is what comes to mind. Anti-inflammatory meds are used to treat it.

I was also thinking costochondritis. It’s very scary feeling too.

A bit late, but another culprit that I often get, is pleurisy. The difference being that Costo is inflammation of the rib/breastbone cartilage while Pleurisy is inflammation of the chest wall/linings of the lungs.
Both conditions usually resolve within a couple of weeks but due to a underlying condition, I find that at times it can reoccur frequently and just feel as though it is a singular occurrence that doesn't resolve for an extended period of time.

Yes--this is costochondritis and it is awful. Doctors downplay this but there are people that have had this for over 20 years or so--I hope that is not the case with me or you or any of you but it is not just a 3 month deal. I have it every single day and it mushroomed into thoracic radiculopathy and intercostal neuralgia--post injection. Who knows anymore but I am in pain every single day I had to change my life actually-I can no longer work and that is not a good thing for somebody like me. Hugs to all of you. I do not know if you are on FB, but there is a large group there with costochondritis and the people are awesome.

Take care and good luck to all.

I have this pain - similar to yours. The doctors call it, costochondritis. Sometimes I feel like I'm dying with it. It comes and goes for no reason at all.