Yep, that was quick. I had my fingers crossed for you, but burnout is far more of a lingering thing than we give it credit for.

My ex worked as a senior engineer in the IT industry, a job that was both demanding and fast paced, AND somewhat abusive, and she quit in July (didn't go back after the holidays) and did not start another full-time job till March, 21 months later.

Just give yourself some time and don't be too hard on yourself... this was NOT a "failure!" I'm glad you have good support!