Correct passcode not working. Phone security locked

So my passcode on the starting screen is not being accepted anymore. I have no idea what happened. I used my phone during lunch and when i used it after 30 mins, it showed wrong passcode. I tried carefully and slowly entering my passcode but nothing. My phone is locked for 60mins. I do not have backup data and i just cannot lose my present data by resetting it. Can someone please help me??? i did not change anything or settings. It just is not accepting my passcode suddenly.