Your account should be marked as severe spam or you must have done something illegal. they would have sent you a warning mail, didnt you get that ?
if you make gmail account with mass created program, soon or later your gmail will temp banned, and must verified with phone.
The same happend to me, didnt think i would have got it back - but luckily did. Basically dont break the TOS or make sure your info backed up.
where you using it to send out spam. Cause that happened to me once. If you send too many emails out in a short amount of time.
This happened because of some gmail problem. Now just take back-up of your Email account so in future . you don't have to worry.