Hi,
Does your mouse look big as well? Because if it is you are right about the resolution being too low that's why everything looks big. Try to right click on your desktop screen without hitting any icon and select Resolution. Adjust it to the recommended resolution then click Apply and OK then see if it would resolve the issue. If your mouse looks normal just press CTRL+ATL+DEL at the same time and select Task Manager. Click on File then New Task and type in explorer.exe then click OK, see if you'll get the task bar back.
If these doesn't work try loading in Safe Mode and run System Restore, restore it back to an earlier date or time before the problem even happened.