I can tell by the leaves it was overwatered (are there drain holes in the cup?). That is part of the droop problem. Now it is likely rootbound, unless the overwatering stifled the root growth, which presents other problems. You will have transplant.
If youre going to go all the way in just a beer cup you have use clones and switch to 12/12 right away. And then you will have to water everyday. Maybe even twice.