Suicide is the most selfish thing in the world you can do! I've experienced it within my family. Your family already sounds like it's pretty shit, if you care and love your family the way you seem to say you do you wouldn't want to put them through anymore pain. Alongwith this girl, she obviously has come to a point where she doesn't feel you are right together, right now. Mayeb it could work in weeks, months or years to come. If she is your friend aswell as a big love why put her through that pain, as she will feel it's her fault. If i was you, i would go travelling and get away for a bit. Whilst you are under 30 you can get up to a 2 year visa to go to OZ as a working holiday. You'll meet loads of people, earn some money and get to see so much more. Thats my advice!