No, your XP Level has not been reset! The progress bar below your Player Banner shows your current Tier of Rocket Pass.

Your Rocket Pass Tiers will reset at the start of each season, but your XP will stay for the journey! Your XP Level is also tied to the progress from your Primary Platform.

To see your XP Level from the Main Menu:

Select Profile

Select Career

Select Stats

Your XP Level will show on the first line of Stats with the amount of XP needed to reach the next level.