How to know what you want
If you don't know what you want from life, it's because you don't know who you are. Therefore, becoming clear about what you want and don't want from life could very well be the most important things you could do for yourself in terms of finding your true self.
When you know who you are, you'll know what belongs in your life; if you don't already have it, you WILL choose to have it.
You will know who you are by observing what's happening in your life right now, by accepting that the content of your life is there as a result of a previous BEING choice. Everything you have in your life is there because it belongs with you; it fits who you've chosen to BE.
So, now might be a good time to take inventory of the circumstances, conditions, and relationship unhappiness you have in your life that you could do without. Allow yourself to see that those problems exist because they fit who you are BEING.
Now, ask yourself who you would be BEING if your problem were no longer there. Again, notice that this question takes your right past your perceived problem to BEING its solution.
If you still don't know what you want, make a list of what you don't want in your life and then make another list to cancel out the don't want list.