I have unnecessary clutter at my home. It is driving me crazy. How can I get rid of this stuff quickly, as I want to sell the house and move away?

Donate it to Goodwill or Salvation Army. :0)

Doing one room at a time, create four piles.

Pile 1. Things you use regularly.

Pile 2. Things you use but won't need any time soon.

Pile 3. Things in good shape but don't use.

Pile 4. All that stuff that needs fixing, but you haven't fixed, any mismatched and miscellaneous stuff you have collected, anything stained or damaged. 

Then put pile 1 back in an organized fashion.

Put pile 2 in boxes so they are pre-packed and out of the way.

Donate pile 3.

Throw out pile 4.

Give away to family and friends, Garage Sale and donate to the Women's and Children Shelters and homeless shelters and homeless veterans center.

Large tedious jobs are best done like you would eat an elephant.

One bite at a time.

Do a little at a time .. For example .. If you have a closet that is filled with clutter and there's no more room to put anything .. Take EVERYTHING out and put it on the floor ... Collect what you don't need .. And don't use .. Only put back what you can't live without. Then donate to shelters or charities and have a garage sale with whats left.  Then repeat in another room, closets, cupboards and counters.  Over time, you will clear out the clutter and gain some weight in your pocket.

I have heard that places like Salvation Army and Goodwill will pick up a maximum of 2 or 3 rooms of usable items.

Thank would work if you already have "gone through" and know exactly what you want to give away and what you want to keep.

Then you could trash the rest.

Call such donation companies and see what their rules are.