I don't know if it is a good suggestion or not but I am going through a breakup of sorts and as tough as it is, all I can think of at the moment isn't the past or the future, it is the now and my now is telling me to forget it, what will be will be but in the mean time, focus on me, make the improvements that deep down you want to make, not for her but for yourself although there is no shame in using this experience as the fuel needed to lift off.

You will always regret standing still after all. It might depend on how the relationships ended whether the above applies but given mine was simply because we were just travelling different paths at this moment in time, there is no reason why a few miles up the road we won't find ourselves driving in the same direction again and whether that may or may not be the case in this instance, I want the car that I'm driving to get me to my final destination.