First of all, I recommend you to listen to Anthony Robbins "Awaken the Giant Within" audio or to read the book. Its really a wonderful book. It tells you a lot about how to motivate yourself in times which you are experiencing now.
Amazon.com: Awaken the Giant Within : How to Take Immediate Control of Your Mental, Emotional, Physical and Financial Destiny!: Anthony Robbins: Books
One idea that I use to motivate myself is to write down what I want to achieve and write a lot of reasons about how this goal or task does this to me if I achieved it. I usually read this every morning to increase my desire to do the tasks that lead to that ultimate goal.
Another book that I use is called "The mind accelerator Book",which is also good.
Mind Accelerator - Your Manual For Success | Volition Thought House