I just got pulled over and the officer found a shitty fake ID.. Punishment?

So im 20, i used my old drivers license and tampered with it so it would say I was 21... I did this like 2 yrs ago and never used it cuz it was so shitty.. but for some reason I had it behind my real license and I got pulled over for a broken head light.. the officer saw it, took it from me, cut it up, said he could arrest me but let me go... What kind of time was I possibly looking at?