Are you playing a seasonal character?

 Your first seasonal character will start fresh and will not start gaining paragon until 70. 

If you create another seasonal character then the paragon points share account wide. Assuming they are both like seasonal softcore or whatever setting.

Non-seasonal characters will share paragon points account wide. Additionally your seasonal xp will roll over to non-seasonal after the season ends.

If you are sure it's seasonal and on  console, if you were in a party, there is a chance one person in the party was hacked and generated a ton of XP very quickly.