welcome to the forums!!!
does it give you any option to use your gmail password to get your phone re-unlocked?
this has never happened to me but i've heard people mention that it would ask for your gmail password to get back to your password menu.
in any other instance, your next step would be factory resetting your phone from the stock recovery to get your device back usable again.
what you would want to do, have your device completely powered off. it will be either a combination of either holding down the up or down volume button, sometimes both along with the power button to boot into a mode what's called "recovery" which you should see a little green droid dude (on some devices at least)
from here you'll want to use your volume up/down button to navigate into the menu, you should already see the option to factory reset from the list. use your power button to select it.
after it does it's thing, you should be good to go.
cheers