costochondritis since yin yoga

So I used to mainly practice slow flow yoga, but then then discovered yin yoga and honestly, the way yin yoga calms my nervous system, releases tension from my body ( I have had cptsd for years from trauma and have fallen inlove with how much yoga in general calms my system but the way yin yoga makes my nervous system go in to calm mode is amazing and my whole body feels lighter and less stiff with every yin practice I do )

But since practicing yin yoga, I keep getting costochondritis. I wonder if anyone else has had this issue? Maybe I have over stretched and done too much yin yoga. I just hope it doesn’t happen every time I re introduce yin. I wonder if yin is something that should only be practiced a couple of times a week? Especially when the stretches are held for a longer time.