I took my iPhone 4 apart to replace the proximity cable because my power button was stuck. After putting everything back together, I was unable to close the rear cover because the upper right corner budged up. However, the phone turned on fine and the screen was functioning properly.

I took apart the phone again to realigned the parts so I can close the rear cover. Now, when I turn on the phone, the apple screen shows up inverted. I have a white background and silver apple. There is also a black dot/smudge on the upper right corner.

The top of the screen is also flicking a little. (One or two lines).

Did I break something and is this repairable? Is the phone beyond repair/not worth repairing?