How can you love someone one day and then decide the next you don't?

OK I know my blogs are probably, well is the most depressing blog you will read, but I have to let my anger out some how. I am 20 years old, and I don't have the slightest clue with what I want to do for a living and I'm still living with my mother, although she is the greatest mother on earth, (I know my opinion lol) I do think it is a little sad to still be living with her. I'm not going to college right now because I have no idea where I want to go or what to go for. Anyway, I am so tired of just sitting around the house with nothing to do. I am so tired of being mad and i don't know why I can't just move on, because in all honesty my father never gave a crap about me! I'm trying so hard not to become a sexist,but I so wonder if there is any good men out there. It is so hard, because every single relationship, of any kind, has sucked! I maybe crazy for saying this, but i just can't seem to understand why someone can pretend for 19 years that they care about you then all of sudden decides he don't care about you anymore. Why can't i just not care anymore, instead of feeling this pain. It sure would be heck of a lot easier to deal with. hopefully someday I will be able to just forget about him, but it certainly isn't in the near future. Its not just the crap he said or did to me, but how he treated my mother and my sisters. No one could never do anything  right. That man is so stubborn that I think if you told him the sky is blue he would argue that it is green, just so he could argue. He has the nerve to tell me that he knows how it is to have arthritis, (I know arthritis is nothing compare to other diseases out there and that is not what I'm trying to say by any means),  and he don't have it! He would just argue with me and tell me what I need to do. I was going to New Orleans Baptist Theological Seminary to become a missionary, but I am no long er going there. He would tell me over and over again that I am not going to be pay for that job. I told him that God would provide for me and he would say God wants you to work for your money! I said I just want to do what God wanted me to do. He would say he wants you to go get a real job! I believe with all my heart God can get any one he wants to saved, but I think it would take Jesus himself to come and to save him personally! I know I probably should not say that, but I can't help, but to believe that.  If you read this remember one thing, that I am a true christian and I love Jesus with all of my heart, but I am only human and i have to let my anger out some how. Anyway, I hope if any man is reading this please ignore my comments about hating all men, i rattled on sometimes lol. I don't really meant it