Hi Riang,
I see that you have the Adobe PDF pack subscription which does not include the Adobe Sign individual account.
You have a free Adobe Sign account that provides you 5 transaction in a 30 days cycle.
I can see that you have already reached your maximum transaction quota as you have sent multiple documents on 4th March 2018.
It works on a 30 days cycle from the day when the document sent.
So you will be able to send the next document after 30 days from the date when you sent the first document (i.e 4th March).
Let us know if you need any further information.
Regards,
Meenakshi