So you desperately want your ex-wife back and you don't know what to do? The road to getting your ex-wife back will need to start with you, you are probably thinking what do I need to do? I did not leave the marriage? Before your wife left you what was the argument about? or what caused her to leave.
For the relationship to break up there has to be some insecurities on her part in order for her to leave you. What you need to do is to look at your whole marriage as an outsider, look at it what may have caused the break up or what was said in order for her to leave you. Most relationships don't just break up straight away, there is always a lead up to it and you need to find out what that is. Get a pen and paper if you can't remember and write down the earlier days discussions, sometimes things make sense when you see it in writing. The next thing you need to look at is yourself, the physical and the emotional side.
Look at yourself in the mirror, have a haircut get a shave, tidy yourself up. You are going to put yourself in a different frame of mind and start to think logical. Tackle one thing at a time, so you don't feel totally stressed. Try and communicate with your ex wife and the key here is to stay calm, honest, rational and respectful.
If she does not want to speak to you then respect that and back off, give it time and try again. In the meantime get yourself in order, go to the gym get rid of all this pent-up emotion, talk to counsellors. See each day as a new day for you to try to get your life back in order, whether it is with your ex wife or not.