How do I overcome laziness?

I have all the opportunities and support I need to achieve great things, but the problem is, I have a deep sense of tiredness any time I want to do something useful to myself.

I can watch movies for 24 hours and not get tired, but the moment I get a book, or try to do something productive, it would be as if a door just closed and my whole mind and body would shut down.

Please advise, how can I overcome this? In my sober moments this gives me serious depression, as I am not getting younger.