I can somewhat relate, man. I've had this problem ever since summer after college where I just sleep all day and play video games all night (replace Hitman with GTA V: Online). Heck, I can barely get up to do simple chores. I was getting up and exercising each morning until I got depressed and stopped. It's getting to the point where I seriously need to get out of bed and do something, lest this habit will become destructive.
Even though I am still trying to navigate through this funk myself, I have come to realize this:
Motivation is key Whether the motivation is good or bad, I feel it is crucial to have this. The motivation can stem from yourself, others, your grades in school, your future, or anything else you see fit. For me personally, if I don't get out of this funk, it is seriously going to negatively affect my future and those that will be involved in it. That's enough of a spark for me to be motivated, though the actual process of being fully productive won't happen over night for me.
I agree with chuck about taking small steps. Any step foward towards an ultimate goal is a good step, no matter how small.