I agree it is difficult to adhere to a schedule strictly.I should also be studying now but i am here at the forums.
In my opinion, your situation is not really bad because even though you do not follow your schedule, you still get your things done at the end. Frankly speaking, it is almost impossible to follow the same schedule everyday for there are always things that may crop up eg. new tasks or family matters to deal with.
So i really don't think there's a concern there. Having a schedule is one but accomplishing what you want to/plan to complete is more important.
For instance, i know that after leaving this post, i will get back to studying and i will finish what i need to at the end of the day
