This has likely been going on for a while - the only thing that has changed is that you know about it.

My suggestion is that you do nothing right now other than take care of yourself. An appointment with your therapist is a good place to start. Any decision you might make right now can still be made later but a decision you make quickly and without careful thought (after you have calmed down) you may not be able to undo.

Of course you are upset, who wouldn't be? Use your support system - you need it right now.