I think you've got some good advise already, but here's my 2 cents anyway.
1) Are you suffering from clinical depression or are the external factors depressing you? If it's clinical depression, look for professional help at once, you'll be very happy you did. If the problems are external, I would make the following suggestions:
2) Find a job. Not having enough food is going to make anyone feel depressed. You're well educated and proficient in computers. I would say find a computer related job and be willing to be flexible on the job so you can get out of this bad place you're in right now. If you can't be flexible, don't get an IT related job. Since I don't know your full skillset though, it seems IT would be easiest. If you do get the job, don't mention free software. Learn what is expected of you first, do your job well, and then slowly and tactfully and when you've gained people's trust and respect, try to steer things in the direction you want. Obviously, look for a GNU/linux related job as opposed to a Microsoft one.
3) Spend most of your free time looking for this job. There are some good books to help you get into the right mindset, by Hillary Rettig. Look her up on your search engine. You can buy them on her website free of DRM for a dollar or two and it/they will help you.
4) Find activities you like and do them with others. Hopefully some are outdoors. Not sure where you live, but you can find a club or a gathering (reading club, chess club, sport club, hiking club, etc.). That's the first step to meeting new people with similar interests. Focus on the interest that brings you together and leave free software/unfree world stuff out for now. The world will usually not come knocking on your door. You must go out there with an open attitude first. Opportunities will start coming up the more you go out and connect with the world.
5) Don't over share. I remember at some point visiting your website and unexpectedly finding a nude photo of you (if I remember correctly). I understand wanting to break taboos as much as wanting everyone to use free software, etc. I can see that your intentions are good. However, over sharing and pushing things unto others may turn them away.
6) As hard as it sounds, try not to overwhelm people you know/meet with your negative feelings/thoughts. You will have a much better response from others if you focus on the positive. It sounds a bit sad to say, but most people feel they have their own problems. If you wish to have friends/get a job/etc. try to focus on how you can improve the life of those you meet. This will have a crazy positive effect, people will come to you, you will feel happier. We all want our problems solved. Become a problem solver for others. It will come back to you one way or another. Though don't expect it to come back necessarily from the person/people that you helped.
7) A woman once went to Buddha asking for help bringing her dead husband back to life. Buddha agreed to help and told her he needed some ingredients first. Among the ingredients, he asked the woman to bring back a single grain of pepper from a household where nobody had ever died. The woman went away and spent a long time looking for this grain of pepper. Eventually, she returned to Buddha and told him: "I understand." You see, there is no household that has not seen death. It is natural. It is a part of life. Likewise, there is no human being that does not suffer. Suffering is a part of life, as is pain. Once you accept this, it is easier to focus on finding your inner peace and making your life richer and more meaningful by connecting with others.
I hope this helps. I cannot stress this enough though: If your depression is clinical, seek professional help. Don't try to be tough. It is like trying to brave a serious illness with no medicine. If it is a physiological condition, you can get medicine for it and feel better.
You can also look for a psychologist (or a career councelor) to help even if it is not clinical (though I'm not sure if there is a free service in your area). Look it up, there may well be.
As cheesy as it sounds, rough seas make skillful sailors. Take this opportunity to learn about yourself and become stronger.
Put free software on the back burner while you fix the things that are making your life unbearable. Rettig has another book called "The Lifelong Activist," which is very helpful for activists who don't want to burn themselves out (she's friends with RMS btw). You are no use to yourself, to your loved ones or to the Free Software Movement if you are burned out.
Don't obsess with one thing or another that can make you feel like there is no way out. A couple of quotes related to this:
"What consumes your mind, controls your life." "Your focus determines your reality."
