Disk Fills Up During Time Machine Backup

[agcamp]

I bought a 1tb external drive and started a time machine backup because my disk had been acting up. I have a 232g drive and at the time I had 15g free space. Part of my disk problems were caused by the disk almost being full but i emptied trash and moved photos to my ext drive. That freed up the 15g I had when I started the time machine backup. Now I have 250m of free space after doing nothing to add the 15g back onto the drive. I had to force the computer off after 4+ hours and nothing was going on with the backup and my toolbar at the top with the apple had vanished and some of my icons were not functioning. How can I free up the space that the backup took and also, how can I see what is on my mac as I can't believe that I have 232g of data on the machine. Thanks for listening and I appreciate any thoughts you might have.