You say that shes the one you want to 'start your life' and family with? Does she know this? How does she feel about this? Not many people of 21 years choose to start a family these days. To a majority of level headed woman , having a family in their early twenties is not on the agender. Perhaps she feels sufficated and needs the space and feels you do too. Perhaps you were tied to the each other hips and were seeing each other far too often and therefore making the balance unequal. I worry that you state 'start your life', believe me there is more too life than family life, (that can start much much later these days). I assume that you saw each other very regularily, perhaps daily!? If you get back together, see each other less make your dates as fun as possible and put out of your mind family life, for a few years.