Sorry to hear about your troubles Matt.
I have recently come across Heart Coherence Breathing which has greatly helped me. I have hesitated to tell you about this but its effects upon me have been profound in a short period of time so I thought I would mention it.
It is a very gentle exercise only employing belly breathing to a set rhythm for 20 minutes (think of it as inflating and deflating a balloon) and is widely discussed in the breath community, easily found on google.
Take A Deep Breath has a 20-minute guided YouTube video if you’re interested.