I can totally identify with your predicament. My tbi was last November as well, and I too have scarcely left the house since. When I was seeing a neuropsych, she referred to it as setting up a "post concussive cocoon." (So here's to hopefully taking flight again ).

Likewise I have lost touch with friends, except for the occasional short conversation, which ends up potentiating my symptoms more than easing my loneliness. But I completely sympathize with your feeling alienated, and all of the stress and paranoia that sometimes accompany it. But as you said, this is merely a step on the path to recovery, as interacting can often times be too overwhelming.

So during the time that you must be alone, I second Laupala's suggestion about taking short walks in nature. Of course, depending on where you live, keep an eye out for deer, and squirrels loosening acorns from high hanging tree branches. Lol. But besides that, it is a great way to rekindle that feeling of connectivity, which I have found can become quite diminished amidst the bustle of the high-tech, always-on urban/suburban life.

Oh and I have also taken up doodling just in the past few weeks, and this for me has been very therapeutic. If there are any thoughtless (not mindless) hobbies you can try, certainly ones that don't require electronics or wordplay, perhaps that will be another outlet. But I wish you well, and best of luck with your therapy.