Another cat might help. There are some steps to take to make sure they get along, though.
1) Find a cat who has a similar energy level to the one you already have, and is close in age. A cat too much older and slower, or younger and more fragile, could get hurt or annoyed by a rambunctious cat, even if he isn't trying to hurt.
2) set up a separate room for the new cat, wiith food and litter. Don't introduce the two cats immediately. Let them spend time sniffing each other under the door, possibly feeding one on one side, and one on the other, so they associate each other with good things. pet on cat and then go out and pet the other, mingling scents. It may take several days before the cats are calm enough to introduce to each other. Be patient and don't rush. If the cats are rushed into meeting, and an argument ocurrs it will be much harder to get them to get along later.
On a happier note, if you do find a compatible companion for your cat, they can have great fun together. My two boys occasionally look like they are fighting for real, but they are never injured and the "fights" usually begin or end with one or the other getting a lick on the head. They chase each other and wrestle, and wear each other out.
They will always want some attention from you, but it may be a more reasonable amount and not "Every moment you are here must be spent entertaining me"
Dr. Seuss~DLH (brother's cat)~June 2007-
Misty~DSH (my cat & Mooby's mom)-?-
MooBoots(Mooby) ~ DMH(Mom's cat)~July 21, 2008-
Sunshine~ Golden retriever X white german sheperd (Dad's dog)~October 24, 2008-