Aerides, I think you hit it on the nail. The release of stress from getting rid of all that debt felt so good. I like my job, so I doubt I'll feel the same way if I choose to quit or even better getting fired.
My life is rich and I'm very blessed with a wonderful DW, awesome kids, good family, and interesting job. Plenty of things in my life to celebrate. I just need to find a goal that'll make me feel exhilarated again.
My reading of your second paragraph is that you like your life as it is right now and may not really want to retire to something else. That's a good thing! FI doesn't always need to have RE follow it immediately, as others on this forum have pointed out many times over the years. It can be its own laudable goal.
So, what kinds of thing might make you feel exhilarated again? I would suggest spending some time giving that careful (and wide ranging) thought. Writing a novel? Developing an intense outside interest? My father-in-law was a pocket protector wearing, calculator on his belt, linear, analytical thinking engineering professor who developed a lifelong interest in 18th Century American and British silver--coffee urns, sugar tongs, etc. This gave him opportunities to enjoy other parts of his mind; when he retired he loved being able to spend more of his time on this. Upon his death we consigned to auction the 200 or so pieces he had so painstakingly researched and collected but kept the 4 or 5 that he often brought out to show us, time and again, teaching us in his professorial style much about their makers, their use, and how he tracked them down -- all with almost childlike glee and an unforgettable eye twinkle. Each time we take these out (or use them in dinner parties) we are reminded of his exhilaration and share it.
For me, I felt intense exhilaration at achieving first the $500K mark, then $1M, but somewhat less so after that. So, I focused on THE DAY of FIRE and concocted all kinds of rituals of enjoyment and celebration in my head to sustain me. Eventual ER felt more like falling down exhausted at the end of a marathon and it took a few months to get up again. But once I did it was like Dorothy in the wizard of oz when the film switches to color! Ah, this is what it is like. Even better than I had thought or hoped for.
Yet, I find I still need to have new goals to go over in my mind, like talismans to rub with my fingers, replacing those that have faded a bit in their intensity. Right now, it is new experiences, derived mainly from travel and interactions with others. I plan our trips a year in advance and look forward to them with glee. I volunteer to work with young(er) people (graduate students) as a mentor/coach and interview candidates for admission to my alma mater. I've stopped coveting things; now I live for experiences. This is my exhilaration and I find it is more than enough!
-BB