I am depressed

Well, might set a long term goal of decluttering. Do not be discouraged if you realize it may take several days or weeks because the time will pass either way.
I do not know how big a mess we are talking here. Usually cleaning up hoards of junk does not happen overnight.

I would say first thing is start in one room. Create a small area in the room to organize smaller things. Right away you can see results and that can keep motivation going.

With really bad hoarding, yeah it seems overwhelming and hopeless. BUT, just work on small cycles of ridding junk and organizing important stuff. Eventually it gets to where even if you throw away very little, at least what is left is organized.