Sad, lonely, depressed and had enough of life?

hi, im 15 and im sick of life, I have no real friends, no one appreciates me ive never had a girlfriend and im sick of being alone, every time I try to to socialize no one in the group lessens or cares, I no no self esteem, I have no vision of the future I see is loneliness. recently I was heat broken she likes someone else and I just cant let go and the pain stays with me. and im just sick of spending all my life in one place alone as theirs nothing else to do. but many i have just had enough of being alone. everyone else has had a girlfriend apart from me. my motivation for life is zero and I see nothing worth living for, I all ways keep breaking down and crying and I all waysthink of suicide as that looks like the least painful out. ive just had enough of being alone in my life I just want someone to be by my side but no one likes me :'(