Nostalgia is a huuuuuuuuge driver for a good portion of my absolutely unnecessary purchases to be honest, so I totally get it. I feel like you have a couple decades on me at least.. and I'm almost on your level already.. so I'm gonna be suuuuper bad once Im your age

especially considering that.. between the time you were a teen and today.. things haven't really gotten THAT much shitter in the grand scheme of things.. but between the time I was a teen and the time I'm your age.. the level of enshittification is going to be many many magnitudes higher.
I also have enough of my mother in me where if I notice something on a deep sale that I *might* need in 8 months I'll just go ahead and buy it... Just to find out after 8 months that I actually didn't need it at all lol. Just cant pass up a good enough deal..
A good portion of hoarding is just a... slightly convoluted survival instinct/ financial self preservation type thing when you boil it down far enough.. especially for the folks raised by great depression parents and those who simply grew up as 'have-nots' like I said.
Peace of mind plays a factor as well. Like me personally... I have enough "survivalist" & survivalist adjacent gear & supplies laying around that I'll likely NEVER use In anything close to their full capacity because I'll (hopefully) never find myself in that sort of situation... But it's an incredibly good feeling knowing that I'm better prepared than most everyone else should shit go awry in a big way.. and peace of mind is incredibly important to ones overall mental health.. that goes without saying. I can probably thank the boy scouts for a good portion of that.. "always be prepared!" Lol. I generally use all.. well.. MOST of said gear while camping at least so.. while all that gear isn't a COMPLETE waste of money & storage space.. it's still all very under-utilized and mostly gathers dust.. especially since I haven't been camping in like.. 3 years.
Makes me think of a song by Slayer called skeletons of society. The lyrics tell a story about some sort of cataclysm that well... Pretty much destroys society as we know it.. presumably nuclear Armageddon.
"Minutes seem like days
Since fire ruled the sky
The rich became the beggars
And the fools became the wise"
It's pretty clear that 'the fools' in the overall context of the song are the nutjob preppers with 14 years worth of freeze dried food and doomsday bunkers and enough arms&ammunition to conquer a small African country. Those folks get laughed at and mocked.. called paranoid.. unhinged.. whatever else by 'The rich' who are quite literally blind to reality thanks to their affluence.. believing that nothing bad could ever happen to them because they've never had to struggle and are too caught up in their own vanity & social status to recognize that things very well may not stay the same forever.. well... If the proverbial shit does ever hit the fan.. the majority of the rich ARE going to become the beggars.. very quickly.
Anyhow..
Considering your living space is fine.. and it seems like you just have a bunch of "yard art" and more utilitarian USEFUL stuff.. I'd say you're just worrying too much. You COULD probably pare down your 20 tons of various vehicles into a more reasonable 10 tons lol.. lose a bit of stress over the whole too many projects/not enough time dynamic and be alright..
... But if it makes YOU happy owning all this stuff.. well.. **** it

Keep it all. Get some more even.
We only have one life to live, and lives are best spent while HAPPY. Living in a constant state of yearning is bad for the psyche.. do some soul searching and find a good balance. You'll be fine