Everyone keeps screwing me over?

why is it that all my friends dont understand my problems? its like when i try and talk to them about my problems they just think they arent serious and give me no advice at all. they think im being a baby about things. and i have some serious problems its not minor. like life effecting problems. no one gets it cuz they dont know what it feels like! i just wish for once someone wouldnt stab me in the back and be a true friend. how can i overcome this? i cant wait for the day when they have a serious problem and i can laugh in their face like they did to me! i did noting to deserve this at all! ive been good to everyone who has come in my life. and instead i get a cheating bf and my family is dying. and lack of friends. :( i have no one to turn to..this is my last resort. :(