I've got hoarder tendencies too. You can't do a declutter all at once, it's too much emotionally. Accept that it's going to take a few goes to fully declutter an area.
You say you've emptied everything out. That sounds overwhelming. Can you collect up one category of stuff from that pile, then throw a blanket over the rest so you're not looking at it constantly and can focus on the new, smaller pile of a single category.
Let say it's eg ornaments. First find a box, cardboard is fine. Take a look at each ornament and decide keep or throw. Hopefully you can get rid of some. If you want to keep them all, pick one that you're less attached to than the rest and let that one go. Box up the ones you're keeping so they're tidy at least, even if the box is in the middle of the room. I know decluttering one thing doesn't sound like much, but it's a start. When it's draining your emotional energy to do it, to pick that one thing, you need time to feel your feelings as part of the letting go process.
Next time, go back to the box of ornaments and decide which ones you actually like to display and which ones you're keeping for the memory they provoke. The memory ones don't need a physical item, take a photo instead then let these ones go.
Do these first two stages for every other category of stuff in your clutter pile. At the end of it there'll be a neat pile of boxes, albeit possibly in an awkward place. But that's fine because they're not staying there long term.
At a later stage when the house is clearer and your clutter pile is now boxed up in categories, return to your ornaments box. Take a look at the space available in your home to display ornaments and decide how many you have room to display. This probably means getting rid of some. Be ruthless.
If you haven't already tried it, I'm doing FlyLady (on the Fledglings thread here, not the website). It's helpful because it's easy. All I have to do is click the link each day and do what it says.