This is why I never use a pin or pattern. Not much you can do really. And don't believe these programs that say they can bypass the lock screen. Most of them are not free and most do not work.
You are going to have to do a hard reset which, yes will erase all of your data on the phone. It will also trip Google's security feature called FRP(FACTORY RESET PROTECTION). you will need your google account info that you used to set the phone up originally.....so make sure that info you have is correct before doing the reset.
Sorry but this is the only way to get your phone unlocked.