She loves what you provide her, not who you are. She doesn't look at you and see someone she respects, she seems someone safe who wouldn't hurt her, someone she can count on. But what happens when you need her and you aren't able to provide for her, what happens when you get sick, get cancer, have to quit your job and be ill? 

Your relationship feels flimsy because she just told you it is. You stayed with her when she was sick, do you feel resentful for it? Probably not, because you don't view her as what she can do for you, in totality. Everyone does it an extent but she does, totally. Its all about what you do for her. She clearly stated it. So now you know the shaky ground your marriage is built on. You are essentially waiting for the shoe to drop. And now you feel unloved and untethered. Now you know who she really is and what she really sees in you. That has to fucking hurt and I'm so very sorry, you deserve more. Anyone who loved and respected you would have kept that to their grave, but she offloaded it so now it's your problem.

I suggest individual counseling and then after a time couples counseling if you are still in. But eventually you will either get over it or you won't and you'll need to do something about that. The only way to know which will happen is for you to start metaphorically mining this with a professional.