I don't know about a vagus nerve stimulator, but have you tried singing? Especially just ohm style chanting and focusing on the vibration it creates in your body literally soothes the vagus nerve. I also do singing and chanting every day.

EFT tapping technique is also good for disrupting ruminations of cPTSD.

The alpha-stim is the only thing any doctor ever prescribed to me that actually helped. It's a very weird sensation, but not bad. And then it like, forces my brain into the correct frequency. I had a ton of different medication prescribed especially when I was younger and all of it was terrible, but this has no bad side effects and is the absolute most effective thing I've ever used.

I think it's criminal that it's not the first thing tried instead these pharmaceuticals.