ok, in 99% of the case it is 24 hours, you see the policy here
From the moment the limit was placed.
Ensure you wait this out in its entirety and if you still have the limit, then you will need to request it is released here
It is rare you need to do this as nearly always, especially on a first violation it will lift, but if not and you are 100% sure its longer then 24 hours then you need to use that form.
If they event they reject the request, then they have labelled the account as a spam account and you would need to create a new account and forward emails from this account to that one via the gmail fetcher (so it retrieves them, avoiding the sending limit) which you can set up with these instructions here
These are all options you have in your situation.
If you would like any additional information or assistance, please do not hesitate to let me know.
And if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.