if you're ready to listen to advice....
Get a job. Ride your dad's bike all summer while you save money. When you get $1000, go treat yourself to a nice brand new bike with a warranty and free tune ups. You'll love the bike so much more after having worked all summer for it. You'll be stress free when something goes wrong, and you'll get a much nicer bike than what you currently have.
If you want a really nice bike, get something used again, but shop better. You could get a full 105 carbon bike for $1,000....
Also, stop shopping by colors and designs. Shop by the bike that has the components you want for the price you want to pay. I'm not saying go get the ugliest bike you can find, but you're pulling up decent bikes just because you like the colors...