Start working. Seriously. Do you have a checklist somewhere? Pick an item and start working on it. Indecisiveness will just make you bored and worried as the time slips away. Start doing something, finish it. Then do something else. When you get tired take a break then work some more. This is the basis of productivity, and will keep you busy for most of the day. When your done with your work, take a nice long deserved rest.
If you find that you are consistently getting distracted by the same thing, and you don’t have the willpower to stop yourself, then make small task list. Do the easy things on it until you can pull yourself out of that environment. Doing small activities will help you build some momentum, and at the end of the day you will have something done instead of nothing.
At the end of the day you want to be able to show yourself you did something. If you can’t. You might lose hope. But if you can you can prove to yourself you are capable, and you can work harder the next day to do even greater things. You’ll get back on your feel, and before you know it back to former levels of productivity. You might even surpass them again.
Even if you do go into a slump, it doesn’t have to be long term. You can have a bad few days, and every day work a little harder to get out of the slump. As long as you work on the basics and continue to do small tasks and prove to yourself that you capable you can keep moving forward. You will eventually climb up the mountain back to the top.
Don’t think you have any hope? Drowning in depression? Then get some good sleep, eat, and take care of yourself. If your body isn’t up to it your mind is going to deteriorate. At the end of the day if your starving and tired your no good to yourself. Eat something and get some sleep, start working again tomorrow. There’s always another day.