Trying To Be Positive

I am trying to be positive as I can. I have plenty of “negative” thoughts that pass through me – stories about how it’s all unfair, lots of “if-only-I-did-this-or-that,” stories, and plenty of stories about the hopelessness and sadness of what happened, how my life is meaningless now and how this is going to ruin the rest of our lives. Some more when you in a long distance relationship, there a lot of negative thinking. hmm... its really hard for me.. but I'm still struggling for it. I want to keep this love forever. owh god please help me.. I am helpless. :(