A few things come to mind:
1. Look at an MPH in public health. The emphasis is on population-scale intervention and research, and would provide you the tools and clout you need to move forward. A lot of prestigious programs (Johns Hopkins) are now partially online.
2. Look for a therapist certified in EMDR. It's almost a miracle tool for complex traumas.
3. I hope you do look into this- as a therapist, I see a lot of kids who spent time in NICU and have severe problems with self-regulation even though they are now physically healthy. I'm sure cancer treatment is at least as traumatizing. Best of luck to you-