There are many here in Newcomers who are in a similar position to you, with S who move goal posts at every turn, leaving them to with their heads spinning.
Zues gives great advice about posting often, on your own thread but also others.
You will find that you are not alone in your confusion, your emotional overwhelm and sense of isolation. You will also find that having a plan to keep yourself as well as happy as you can through this process is essential.
People here will offer love and support and a kind of companionship that is not currenlty available to you in your relationship.
Please be kind to yourself. Sometimes realising that no decisions have to be made right now is the best place to start. I find for myself that attempting to fix something sometimes provides more pain and frustration, than actually stepping back and observing the sitch. Sometimes doing nothing is doing something, and the exact something that needs to be done.
I am also a proponent of a inspired action. An action taken which feels easy and made with real commitment, and feels like a step or move toward something is often more successful than one that is made based on fear, hesitation and a move away from something.
You will find some peace, as V says I internet promise. It will come in dribs and drabs initially and you may not even notice it when it does. Over time you will have more and more moments of peace and your ability to see where you want to be and whom will come into view.