It a human nature to waste time.
We know that we waste time but can't do anything about it. This is because of out of focus wandering mind and a really week will power to something. Why? Because we still don't realize importance of time. And this realization comes only when we realize that we are in some crisis and only we can solve it.
If you know what to do then just motivate yourself in doing that thing!! Just concentrate on doing. Practice some meditation. Watch some motivation and inspirational videos rather watching funny videos. If you goal, set a time limit and work accordingly.