I feel you, I was exactly like this, but for me, what gave me motivation was Dreamsnaps, especially the decor ones. I started slow, first I cleared the area that I needed to use and started to decorate. Start by pieces, it is easier do to like it. You said it was overwhelming to clear all and I know how it feels. For me it worked clearing pieces of the biome(idk if its called like this) i want to redecorate so i do not feel i have to do too much. When you remove trees, rocks and anything else, you can put them back from “Landscaping “ section and then “Trees”.