I have found that eating oily fish and taking amino acids supplements have helped me deal with stress. Any high quality whey powder will have a large quantity of amino acids in it.
I personally did suffer some mental health problems in my teens, during which time I experienced some strong suicidal feelings. But I found that eating oily fish such as canned sardines or mackerel really helped.
Taking fish oil supplements did not seem to help me and I tried quite a few different manufacturers. There is however quite a lot of information on fish oils and trails that have taken place where the symptoms of depression, bi-polar disorder, anxiety, schizophrenia etc have been greatly reduced.
You said computer games made you feel worse, that was just the same with me. Also, drinking anything with caffeine in and smoking made me feel a lot worse, although I didn't realize it until I had stopped.
As far as meditation goes, I think It can be very effective. I went to various Buddhist groups to meditate because I found meditating in a group some how easier than meditating by myself.
There is an easier way to meditate though. There are several companies who produce audio Cd's which actually induce a meditative state using binary beats and change the users brain waves to the desired state i.e. Alpha, beta, gamma, theta or delta.
I bought Holosync's prologue level audio CD and listened to it for about a year and noticed hardly any benefits, but when I meditated after having just taken the an animo acids supplement ( in this case whey powder) I noticed significant benefits i.e. Reduced anxiety, paranoia and other dysfunctional feelings such as, feelings of suicide.
On a side note, I don't think inducing a meditative state while having suicidal, homicidal or thoughts of self harm is a good idea at all because it's probably stress on the brain that coursed these feelings in the first place, and stressing it further is only going to make things worse in the short term.
To summarize and clarify; basically the oily fish made me feel a lot better but if I pushed myself I would still burn out very fast and start experiencing negative emotions relatively quickly. Mediation seems to have greatly decreased this tendency to burn out and greatly increased my torrence to stress. I seem to take things a lot less personally now than I use to.
Sorry you don't like being alone. Your problems are quite different from my old problems, but I am sure that becoming mentally stronger will help you an awe full lot.
P.S. I would not buy a Holosync audio Cd again because they are expensive and you can get a binary beat generator program for free, it's called Gnaural2.
http://gnaural.sourceforge.net/ sry I don't know how to make this a hyperlink.
Edit: oh it makes it a hyperlink automatically