Overwhelmed with stuff

I'm sure my question has been asked in various ways before but here goes. I used to be a die-hard "garage saler". I would go to dozens of garage sales every single week during garage sale season. It was exciting for me to get clothes for the kids, furniture for our home, decorations, lamps, tools, and more all at a fraction of the cost.

I did this for years and years and I'll admit, did not always stick to buying what we "needed". Well as you might imagine, our home is now full. Even though I regularly give things away to others and to charities, we still have too much stuff.

Now here's the problem. Over the past couple of years I've completely lost interest in garage saling. I go once in a while when we really need something hoping to find it cheap but I hardly go at all anymore. I don't want any more stuff and I want to get rid of most of the stuff we do have. It seems strange but I really just don't care about any of this stuff anymore. Is that normal?

And the other thing is, the stuff we still have overwhelms me so much that I keep bringing things to our basement and never do any thing with it all. I just don't go down there unless I absolutely have to. I want to make the basement usable for the kids but when I go down there I just want to run away. It's been like this for almost a year!

How can I get to the next step and get rid of all the stuff in the basement? I'm serious, it totally overwhelms me and I just shut down.

Thank you.