Trouble is that i can't open anything from the screen!
Do you mean that some parts stay out of the screen space (not visible) ?
If so, you could try to boot with an alternative boot option with a resolution of 1024x768 or perhaps higher. This resolution can display enything.
From the graphics screen, you can terminate X (the graphical screen system in Linux) by pressing Control+Alt+Bckspace. This will bring you to the terminal, from where you can power your system off or reboot.
Furthermore, you can use the command
sudo Forcevideo
to start GParted with manual selection of graphics driver and resolution. VESA and 1024x768 are usual "safe" options.
*** It is highly recommended to backup any important files before doing resize/move operations. ***