Well I have sympathy for you, Just don't be an idiot! Don't get upset/angry if you see her out with another bloke, don't try to make her jealous by getting another woman and flaunting her in front of your ex and don't go out getting pissed every night, as when your finished the problem will still be there and you'll still feel like sh!t, you'll just have a lot less money and a hangover.
Most women just aren't worth the trouble, (no offence to anyone on here) if your feeling upset about losing her and are just thinking about all the good times you had together... Stop it!!!
Think about all the positives, no more moaning, no more arguing, you'll have a lot more money in your pocket, you can concentrate on the things you want to do and have time to do them.
Yes it'll still hurt for a bit, but it's not like you'll be alone forever, you will find someone else and then you'll be wishing you were single again.