Hi spacenomad,
If you perpetually cannot get along with your family members, regardless of whose fault it ultimately is, it might be a good idea to try and seriously space yourself from them. You say that you are studying at a good place. Are you also living there (and now are just home for a break or something)? If not, would it be possible for you to move into a dorm or an apartment in that area?
On another front, what medication(s) have you tried to combat these feelings? Were you any better on them? Again, sometimes it really does take a lot of searching to find one that works. As well, do NOT let the idea of taking psychiatric medication cast a "weak" shadow on your character or your intelligence. It's not like that at all.
If you can swing it financially, I think you would do great getting a place of your own (even if it means debt now, debt is better than death). In such an environment, the positives you listed (being intelligent with lots of talents) can take over your life, and you can set the pace for how fast you want to try and build up a social life.
The fact that you're willing to talk to people on here indicates that you just cannot function with people in real life, but could if it were possibly easier (possibly more like online). I think a lot of us think this way, and to an extent by finding the right people, it's possible. You have not yet, but that's to say that you won't.
What you describe as being the average family experience (that is, what you provided via your story) is far from acceptable. I think that with a bit of time in an environment over which you have a bit more control, and perhaps some medical help regarding finding a medication and/or some behavioral therapy, you'd be a heck of a lot better. Families are tough, sure, and my relations with my own are far from ideal (and neither or either side is to blame). But if you can at least gain control of your end, then it's really only their decision to make chances to meet in the middle with you. A lot you might have to work toward, but you can accomplish this.
Sorry again to hear about tonight's incident. But why not just make it the last bad one in 7 or 8 years, instead of the trigger for walking the plank? If you want to talk about anything, literally anything, this forum (and not just this thread) will be here for ya. Keep going man.