1) Keep working on your depression: therapy, consider meds (but only w/therapy), exercise (even if just walking a mile a day), hydrate, eat healthy, etc. Talk with people. Force yourself to get out of the house. This stuff matters.

2) On focus: start with a one hour block a day when you can do no facebook/hackernews/etc, and instead, you have one thing you have to get done. You will feel good about getting this one thing done. Make sure you get at least one non-trivial thing done each day. Work your way up to two hours a day, and then when you can, three etc. (Most non-depressed people are probably only productive 3-4 hours a day anyway:)

Good luck!