Reading this thread, and resonating with much of what you say, may I suggest maybe that it's not the meaning or a meaning, but simply the search for meaning itself (which I realise was the title of Viktor Frankl's book) that might offer some structure.

I don't know if it's our brain wiring, chemistry, experiences, psychological development path dependencies, or what, but I'm pretty convinced that human brains are pattern-seeking systems, and finding and establishing patterns, ordering our universes, is one fundamental drive.

It also turns out that that's what I've been directly and principally focusing on for the past few years, mostly because I can't not.

Several of the activities and compulsions you mentioned above strike me as behaviors which feed the brain's reward systems fairly directly (drugs, alcohol, sex, extreme activities), and your combat and other experiences may also affect that -- not judgement or anything, just mapping for me of "what does the brain seek, how does it work, how is it itself re-shaped by experiences?".

The advantage of taking a shortcut is to get to a destination faster. The advantage of taking the long way around, or exploring a space, is often to get a far stronger sense of the interconnections within that space. I thrive on connections, myself, so that has appeal.

No idea how this strikes you, but offered for consideration.