I'm a hoarder. I have great difficulty getting rid of stuff.
What works for me is dealing with a bit at a time. It could be literally just a drawer, a cupboard or a pile in a corner of a room.
It makes it more manageable. Practically, because the quantities are small and stuff that is thrown out can be put in a bin liner with the rest of the rubbish, and stuff for charity shops is easier to drop off when it's just a carrier bag full.
But it's also easier emotionally. It's not such a big deal, it's easier to do because you only have to do it for a little while and don't get discouraged or sidetracked so easily.
I'm a voracious reader and get rid of books once or twice a year. I put them in big strong shopping bags and take them to a couple of towns nearby where there are plenty of charity shops close together, and drop off a bagfull at each. Doing another drop of books is on my to-do list for tomorrow, and I have to go to the town in question anyway for something I can't get locally.
I've actually got to the point where I like going to the tip. It feels like such an achievement, and I don't feel guilty because an awful lot of stuff there is recycled, and what isn't goes in an incinerator that generates electricity. Admittedly, it's easier for me than for many people: I have an estate car, the tip is only 1.5 miles away and you don't have to make an appointment. It's easy to fit in if I'm going shopping or anything.
Both my parents were hoarders, and I wonder if it's inherited or acquired by example. When they died, I had to clear their house of 30 years worth of hoarding. One weekend alone, some friends came to help, and we took 32 large estate car loads of crap to the tip. They hoarded packaging and old newspapers and all sorts of shite. They lived in Milton Keynes, where there is a splendid recycling place. I left all the decent furniture, crockery, cutlery, good clothes, electrical stuff etc and the charity that runs the centre came and collected the lot.
I really wanted to keep a wonderful 1950s retro suite of white oak bedroom furniture that they had bought from Waring & Gillow when they were first married, but had nowhere to keep it. It would have sold for a small fortune in a Brighton retro shop, and I often think of it and hope it went to a home where it will be appreciated.
OP, all I can say is that getting rid of stuff is therapeutic. The sense of relief and achievement when you have finally cleared a room of useless and/or unwanted stuff is wonderful. But I also understand how hard it is.
I still have my late partner's motorbike gear, I can't bring myself to chuck it away and haven't had any buyers when I've advertised it, despite it being almost brand new. It's cluttering up the floor of the wardrobe, it's really in the way, but I just can't bear to chuck it out. Or the last pair of shoes I bought him. I feel too attached to it, and hope that soon I'll be able to deal with it.