i wana stop feeling depressed

i dont no wat 2 do i keep gettin massive mood swings and i just want to cry for no reason i go to skool and will be talking with friends and i just wana cry so i go to the tolilets and have a breakdown im sick of being sad ive been through so much the past few years and its all taking its toll i hav no self esteem and just want to lie in bed all day i want to be happy to smile to feel normal look in the mirror and be happy with what i see i dont feel like eating anymore and the weirdst things get on my nerves im so sick of feeling so down HELP please