4 months is nothing. be patient.async and sync have been explained SO many times that i am going to let you find out for yourself. have you never watched videos of different 3d styles?and also, your video is very good. it has slow mo and everything. surely from a good video like that you can look at your shuffle yourself and by common sense work out what you have to do? i would have loved to have a video like that of me when i was learning. it makes it obvious what you are doing wrong.SEARCH
if you can't be bothered, then you obviously don't want to learn 3d enough.the reason that the thread is so big is thanks to people like you that have that attitude, and can't be bothered to read.
Asynch and synch are the motion your hands are moving.Synch- Your hands move up and down at the same time. Have a look at Trash's 3D pattern.Asynch- Your hands move up and down at different times. Have a look at Basptiste's 3D pattern.Remember, unwrap the diabolo as soon one diabolo leaves the string. You want them both to fly up.