How to deal with unavoidable failure in my first year of tenure-track applications?
I suggest dealing with the situation by revising your (misguided, IMO) definition of “failure”. Even if it is, as you say, “ineluctable”, that you will fail to land a tenure-track position this year, you will still be a highly qualified and highly successful person with excellent career prospects. To refer to this as a failure is itself a failure - a failure of the imagination, that is.

I and most other successful academics had to spend multiple years after graduation to get a good tenure-track position. Almost all of us struggled with repeated rejections, job uncertainty, and geographic dislocation before arriving at a good place career-wise. Keep your eyes focused on your long-term goals and on the fun and passion of doing research, and given your description of your situation I predict that you will be fine. Regardless of what happens with your current job search, a “failure” you most certainly are not.