The only solution I can think of would be taking the total cred earned up to that point, and adding it directly to the total needed to gain your next level.

So bumuming it takes say 50,000 cred to get to level 11. And I have 110,000 cred (Which is waaaay over the amount required for level 10), I’d have to get to 160,000 to get my next level up. Someone who just recently reached level 10 at 70,000 cred or something will have to get to 120,000 total cred to get his level up.

This way everybody keeps their cred totals, and the game continues as normal. No cred resets necessary.