all nature leads to higher entropy

Its around 19 days till my first exam, in physics. These are possibly the hardest examinations I have ever had in my entire life.
The fact that my friend, whos doing the same course, dosn't bother his arse to do anything is causing me to fall into apathy, which I can't afford to do.
My girlfriend and me are on shaky ground as I'm slowly loosing interest, and I have to move to france for my placement in august.
In a way I wish we could just agree not to be together for that year so I can get all the sex out of my system rather than hurt her.

Is going to France a good idea?
Am i up to the task?
won't I be lonely?
Am I overestimating my attractiveness? shouyld I just settle for her?

Yes I admit it, I'm not over my ex. She lives with me and 4 others, its been over 2 years since we went out, for 5 months, having her parade around scantily sclad is causing me to obsess.
A year away from her will be good, I'll forget about her...unless I'm in love with her..
I think I'm in love with the idea of her but the reality would probably be a huge let down.

I cant talk myself out of it.
I guess I've got to play it as it comes.

This will be a blog concerning love, lust, want and confusion. The difference between lust and want being illustated thusly.
Lust is uncontrollable, to label it with the words insatiable thirst would be dismissive though it has been described by this phrase more often than not. Yet agin the english language fails to have an accurate word to proplerly describe an abstract concept.
The closest words I feel are need and yearn.

The matter at hand:
I lust for a woman who is unatainable,for a few reasons, she dosn't want me being the most obvious and the most desimating of the points proposed.
I am in a relationship with a girl that I think I'm in love with, but don't lust after.
(I want ever other girl I see recently I'm not sure whats wrong with me.)
Bes is currently involved( though not too deeply) with a man called craig, who is really quite ugly, but I have no doubt is a social butterfly (cunt) which is what bes finds attractive.

At this point I'd like to put into percentages the success of any action I could take:

Break up with emma, admit I'm still not over bes and ask her to go out with me again.
likelyness of success: 5%

Break up with emma, dont tell her why.
Bide my time until both me and bes are single and drunk and then make my move.
LoS:25%

Continue with emma like nothing is wrong and end up in a long term relationship that is founded on nothing other than my desire not to be alone.
LoS: 80%

I don't know what to do.
For the first time in my life I'm afraid of taking action. I love emma and do lust after her but I lust after bes and other girls more.
I don't know what to do.