You're not living in some sort of utopia. You know deep down that life has its limits and so do you. Your problem is that you can't achieve everything you want to achieve, and the solution is quite simple: decide what's important to you now, and learn to say no.
The key: living in the present.
Learn to live in the present, without looking back on everything you haven't done and might never do. Then you need to learn how to say no to new projects, new responsibilities and new things you don't have time to do.
Be ruthless, choose well and you'll find it ten times easier to juggle work, your personal and family life and your free time.