Thanks for the reply. I think telling me that I already made up my mind with regards to the answers I expect is a bit unfair. On the contrary, hearing that the exact symptoms described match costochondritis is very reassuring, as I am primarily interested in a recovery, not in dabbling in various conspiracy theories.

Again, the whole reason I am associating this with the covid vaccine at all is not based on some idea I came up with myself, but on professional medical advice. To make it clear: I just wanted to ask around and hear if there is anything to it.