Focus on what you have, not on what you don't have. With the latter, you'll always lose.
About three and a half years ago I was given the opportunity to set up a trade office in Manchester, United Kingdom for the government of the Netherlands. There was nothing yet established and I did not know Manchester at all. Furthermore, right before I left, I met my current boyfriend.
But I did not hesitate one moment in taking the assignment, since I knew that if I didn't take the opportunity, I would regret it for the rest of my life. It became a success and furthermore, the relationship with my boyfriend is better now than ever. In truth, the decision was not that hard, since I don't have children and my boyfriend and I did not know each other for that long before I had to choose, but I've learned some very important lessons over the past three years.
First, consider the source of criticisms over your decisions. Is the criticism coming from somebody whose opinion is really important or whose opinion you should take into account? Many people have expressed their opinions about my long-distance relationship. But they were not my boyfriend, me, our parents, close siblings or friends. They were people I met only once through work who surprisingly had strong opinions on how I should live my life. Their criticisms say more about them than about me.
Second, only one choice in life is definite and that is having children. Any job you accept, any move to another country or city, are decisions you take at a certain moment, but over the course of time can change. Of course, you cannot change things overnight, but there is only one person who can change your own life and that is you. So never refrain yourself from taking an opportunity. Remember that nothing is forever (except having children). The Dalai Lama said it something like this: All is temporary and everything changes.
Third, focus on what you have, not on what you don't have. With the latter, you'll always lose. There will always be people who are richer, more successful, better mothers/fathers/friends/children, and so on. Focus on what you have at the moment and focus on what you want to achieve in life. It is a waste of time to compare yourself with other people unless they inspire you or educate you.
My situation is different from many since I have not experienced the beautiful task of being a mum yet, but these three values help my boyfriend and me to make sure our relationship works now and that we enjoy our lives now. Nothing is forever, enjoy today!