What is meant by the saying, "You're painting yourself in a corner"?

You have arrived at a situation that is unwinable.
Basically the more you do the deeper the hole you are in gets.
You are well and truly sTUFFED

It means you are getting yourself into a pretty sticky situation... just as Cben stated!

What is meant by the saying, "You're painting yourself in a corner"?
It means you are pushing yourself into a corner and there is no way out it often means you are in trouble or you are making trouble for yourself so Don't paint yourself into a corner it means trouble

Paint oneself into a corner:

To do something which puts you in a very difficult situation and limits the way that you can act.

http://idioms.thefreedictionary.com/painted+into+a+corner

Get oneself into a difficulty from which one can't extricate oneself. For example, By volunteering to do more work in the office and then taking a freelance job, George has painted himself into a corner. This idiom uses the graphic image of painting all of the floor except for the corner one stands in, so that one cannot leave without stepping on wet paint.

http://www.answers.com/paint%20yourself%20into%20a%20corner

Paint yourself into a corner

A common phrase or figure of speech where you forget to leave a way out for yourself.

Happens all the time to novice painters. If you're painting the floor, sometimes a shortsighted person will paint the doorways first. Usually they don't catch on until they have managed to cut off every exit with fresh wet paint.

http://www.everything2.com/index.pl?node=paint%20yourself%20into%20a%20corner

If you're painting a floor, it's always good to ensure you finish at where the doorway is, rather than "painting yourself into a corner" and therefore having to tread all over the fresh paint, thus ruining your hard work. Hence the figurative use, meaning having no acceptable options left to take, owing to one's own errors.

http://www.phrases.org.uk/bulletin_board/20/messages/1160.html

Picture the scene: you want to paint the floor of a room. You start at the door, moving backwards, painting as you go. You will reach a corner, with everything in front of you painted, and you are unable to get out, as you are backed into a corner (another idiom).

Hence, 'you have painted yourself into a corner' means that you have done something which means that you are in a position from which you can't extricate yourself.

Politicians do it all the time: they make campaign promises, and find they can't deliver. It's not a serious problem to magically extract themselves: voters have a very short attention span. "The best argument against democracy," someone (Churchill?) said, "is a five minute conversation with the average voter."

http://www.phrases.org.uk/bulletin_board/49/messages/42.html