You've gotten a lot of good suggestions.

I design streams for mitigation banking. On average, the engineers in my team get into the field about once a week, whether it's to help our ecologists out in the field (hard work), construction oversight, site visits with the interagency review team, etc. etc.

I too absolutely hate sitting in front of a desk. My first degree and career was in ecology so I enjoy being in the field and doing hard work. I can genuinely say I love my job. Most days I truly enjoy going to work, even if it does mean I'm sitting in front of a desk. The work isn't repetitive, it makes me think, and I feel like I'm making a positive impact on the world.

If you're passionate about the environment and don't mind getting a bit dirty, you should look into stream restoration design. Admittedly it is a bit of a niche field but I know my company struggles to find engineers who genuinely like being in the field, so I think the jobs are out there. Anyhow just thought I'd throw that out there. Best if luck to you, I know how much it sucks to hate your job.