Look at the psychology of hoarding and you'll probably find things which resonate.
I am much better at it now but used to struggle a lot.
It felt like a waste esp if it was being thrown away. I felt like I "should" donate or sell it, or use it for some other purpose but then the effort required to do this was always too much and I'd never get round to it.
I'd worry about what if I need this later.
I'd feel guilty about money spent on it and whether I'd got the use out of it.
I'd generally feel overwhelmed and not be able to make a decision so I'd postpone the decision and effectively just never actually make it.
I'd worry that I might regret it or miss the item. It's such a permanent decision!
Anyway things which have helped:
Seeing the value of space/curating my stuff rather than keeping literally every item I've ever owned forever
Understanding that getting it out is the most important and not necessarily worrying about doing it the exact right way
Understanding sunk cost fallacy (money I spent on it is spent, it will be whether I keep it for another 10 years or not.)
Not being so skint that we can't replace stuff if we absolutely need/want to. And realising that it doesn't need to be the literal exact version of the one that I had previously. I've bought new versions of my childhood favourite books/board games to enjoy with DC and guess what, it's just as fun. It really doesn't matter that it's not the exact one I had.
Being clear that in order to get better at making decisions I need to make decisions and commit to the outcome. Finding out the thing I'm worried about almost never happens, and when it does it's not the end of the world.