So sorry. The pain is horrible, I know. Not much but painkillers will help in the short term, but the thing that made a difference for me, long term, was changing the way I slept. I suffered from several bouts of costochondritis and suspected after a while that the primary culprit (in addition to a too-soft bed) was sleeping on my stomach with my head resting on my bent arm. I forced myself to sleep on my side leaning against a large pillow and haven't had chondritis since I made that change 9 years ago.
It's been a while since I researched the causes of chondritis, but I recall a doctor telling me that the first time I had it it was probably actually an infection, and that subsequent flare-ups were probably the result of stress on areas weakened by the initial infection, FWIW.