Before you jump ship, consider looking for a less demanding specialty area using the degree you already have. I worked psych for years and can appreciate the stress you're talking about. But that's not all that's out there.
I now work postpartum and I really love what I do. If you like teaching and interacting with (mostly nice) families, you might want to consider this.
How about home health care. I don't know how long you've been in psych or what your background is apart from that, but if you have good assessment skills, you might really enjoy the one-to-one aspect of seeing individuals in their own homes.
Clinic nursing within a hospital, outpatient care, school nursing and office nursing might also be realistic alternatives. Before anyone gets annoyed, I don't suggest these areas because they're "easy" but because they offer challenges that might be less intimidating than the headgames, tension, and subtle threats that can go with adult psych.
It's a pretty safe bet that these alternatives will involve a reduction in pay, but they shouldn't drop you as far as vet tech pay, and you won't have to go back to school. At least not for very long.
When I went from psych to postpartum care, I voluntarily took an eight-week hands-on refresher course to get me back in the swing of using the latest equipment and just generally converting from mental to physical health. It was well worth the effort. If you decide to go this route, contact tech schools or community colleges, as they often give you more bang for your buck.
If you haven't been in psych that long, you might not need a refresher. But either way, I'd encourage you to look at other areas of nursing before you let that expensive degree start gathering dust. If you can make a living wage and still keep your sanity, maybe then you can volunteer your time to work with animals. Groups that take animals to visit schools, nursing homes and hospitals come to mind.
Whatever you do, I hope you'll find a good balance between paycheck and peace.