First of all, do not beat yourself up about it. Hey, writers get the "writer"s block"... I think that each and every person who has projects to do will at one time or another hit that situation.
I am there right now....So what I will do is to start on the item that will get done with the lest amount of time and effort. Reason is that once it is finished I will feel like I actually did get some thing done (which I did) and it is a shot in the arm (so to speak) and I get jazzed up and eagar to start another. Take the next simplest to do and so on and so on. Start small and work your way to that final, big one!
Good luck.