Glenn, it sounds, to me, as if the grass is always greener on the other side. When you are with your wife and children, it is tedious and you want romance & excitement; when you are dating other girls you want the safety and companionship and security of your wife and family. This sounds immature, but understandable in some ways. Are you, though, really settled and mature enough to know what you now want out of life, and are you willing to devote yourself to it?
All marriages can become a bit mundane, when jobs and money and childcare are involved; where you are together enough to take each other for granted, but not enough to enjoy yourselves together and have your own private romance.
Marriages can and do certainly work ~ but they require
work.
And whether or not yours has or could work, you still have two children, to whom you owe dedication and love.
Maybe you and your wife could possibly make things work again, but I think that you would need some help ~ relationship counselling.
However, after all this time, maybe you have left it too late for the marriage, but not too late for friendship, support and playing a real part in the life of your family.
If it works ~ great, if not, then you can still be there for them, playing an important part in their lives, but 'pining' is not going to win her over, positive activity might.
As for dating other women, Argyll might be right, but I'd leave it a while, since you seem to have had problems knowing who you wanted to be with, and dating others added to the confusion.
I'd concentrate on being a good, decent, supportive ex, with no pining, or expectations, or pleas ~ just look after you kids and be a supportive father to them, and give your ex whatever it is she needs to help her.
Good luck!
And welcome to the forum!