How can Allah help change my life around?

Well let me start of by introducing to you how much of a sucky Muslim I am. Many times I break the rules of Islam. I've cursed the prophets, I've cursed Allah, I've cursed everything having to do with Islam before. In fact, I just finished doing so today. I do feel horrible. I used to be decent, and I actually do believe in Islam, but after a week or so I always fall back on the astray path. I am a kafir as of now because of all the cursing I have done. anyways, I am failing in aspects of life because of my lack of religious faith. I am failing with girls, I am failing with my studies, my social life, my exercise, and pretty soon I'm going to europe and I feel like my plane will crash into the Atlantic because of all the cursing I've done. It may sound like I'm crazy and hey I might be but its only in my mind its not apparent in my physical appearance lets just say. Anyways, what does it take for me to do so Allah can forgive me and help me become successful? Thanks in advance.