I think what I am going to say will sound rough and/or a tad rude, but it is likely because she has psychological issues. I mean, we all do to some extent, but there is an averagely healthy range, and then there is dysfunction. From what I read, it sounded like before your wife chimed in, you were just on your way to reclaim yourself again. Nothing good comes out of having to walk on eggshells around someone that goes from sweet to nasty and is controlling.
Questions for you (dig deep before you answer and be honest with yourself): Do you really, but really love her, or do you feel more like used to this person (familiarity, memories, attachment), feel some kind of duty to stay, fear you can't do better, fear of not knowing what lays ahead and the old and familiar is better? When was the last time you and her were happy together consistently? Does she make concessions to make you happy equally to the concessions you make and vice versa?
You see, from the moment you are born until the moment you exit this world, people were, are, and will come in and go out of your life one way or another - we break up with people, people die, we marry, we divorce - life happens. If you look at the big picture, other people are meant to come in and out for varying duration of time. It's how it is. There is only one person that is always there with you and holds your hand from beginning to end, and after that and that person never leaves you and it is to that person, before all other people, that you owe love and you ought to make that person really happy. That person is you! Time to go make that person happy in a healthy way and love that person enough to say, "Ding-dong, crazy wife! I deserve to never have to ask such questions again. I deserve so much better!"