logic and rationalization

I like to reason. I feel like reasoning and logic are the only two things i am really good at. Maybe I'm not actually good at them but I feel as if I can reason the hell out of any situation. That is what makes me a great decision maker.
The only area of my life where this logic seems to faulter is my love life, or lack there of.
logically I should not be thinking of Josh at all. I should not trust him, he has given me no solid evidence of his fidelity toward me in the future.
I have absolutely no reason to believe that when I return to Gainesville that he will not pick up where he left off with zorah and I have been given no evidence that she is not continuously trying to get back into his pants. On the contrary.
I know for a fact that they will continue to hang out. I know there will be nothing to stop him from going to her house when he gets bored or lonely.
I'm not saying that he wants to be in a relationship with her, god knows he has drilled that into me. What I am saying is that I have no reason to trust that he will not be easily seduced again. I have no empirical evidence that history will not repeat itself.
I feel as if i have made it too easy for him.
Logically when something like this happens the person who is hurt does not do all the appologizing and does not continuously put themselves out there to be hurt yet again.
Again, not so much with the logic and rationality when it comes to matters of Josh. I just always thought our situation was above reasoning and logic and was only fit for matters of the heart.

August is starting to scare me.
I am starting to worry that my heart is going to lose this battle and my head will win.
logically I have no reason to trust him. My heart tells me he would never cheat on me. That if we got back together he would be 100% mine and no one else's. My head tells me that even if we got back together with me being "out of sight and out of mind" all is fair in love and war.
We can both agree that he is not ready to get back together with me. But why am I so quick to say I would take him back?
Isn't this whole situation illogical?
I went from being completely distraught and slightly suicicdal to happy?
Does any of this even make sense?
I am so confused...
I just want this summer to go on forever. I am finally happy again and all I can do is wonder.?.?

What will happen when I go back to gainesville. Will he realize that even though I am away I am worth holding out for?
or...
Will the next best easy thing steal his attention while I am "out of sight, out of mind"?