Did you accidently hold or press the 'menu' button when turning on the phone?
That will put it in safe mode.
Press power button, Turn off / power off phone.
Turn phone on again being careful to not touch menu button.
See if that fixes it.
If not, turn off phone, remove battery for couple minutes.
Turn phone on again.
And thank you for the comment by Herbb623. Legalvid, have you tried the steps listed by Herbb623? Was this successful for you?
Please post back with your results.