Hmmm.... I've got alarm bells ringing after reading your post.
First, you seem unhappy in your current job and want to FIRE (not just become FI) as soon as possible
Then - you want to know what degree you should get to give you the maximum amount of money in the shortest period of time.
Finally, to complicate things, you and your husband seem to have vastly different salaries *and* it doesn't appear shared (evidenced by your statement that "DH [can] beat me to [FIRE] by years at our current wages"
Let's start with your current job: Why do you hate it? Is it only the money aspect that is troubling you? If so, I can sympathize - my wife and I have advanced degrees but make about what you do currently (combined). You have a decent amount of savings and so, even without making any drastic changes it's certainly possible to retire by/before age 40.
IF you move to another job - I'd strongly recommend choosing one that actually holds your interest. You aren't sinking in a debt trap, so it's better to choose something you enjoy vs. taking a job with a high salary that will leave you wanting to claw your eyes out every Monday morning. What do you do now? Can you find a job without another degree that might pay you in the $45-55k range? Even a modest change like that could have you FI/RE in under 10 years. Hard to give you specifics since you didn't include detailed spending, but given how you max out your 401(k)s and IRAs it seems your expenses must by very low.
Given this timeline, I'm not sure any amount of schooling in any field will be worth the sacrifice of time and the outlay of cash unless you genuinely have an interest in the job in the first place.
Finally - how would this work with your husband? You appear to keep your finances very seperate (or maybe I"m mis-reading it) - is he ready to FIRE? can the two of you work together to both be FIRE around the same time?
I'm encouraged by your large savings at a young age, but I"m concerned at your approach.