How to get over the guilt of quitting breastfeeding?

My LO is 11 Weeks and the past Monday she decided she no longer wanted to breast feed. She would scream and cry anytime I tried feeding her and then I would cry. It was a mess. She never was a huge fan of breastfeeding from the start so I’m not surprised she’d rather bottle feed. I decided to pump and feed her what I pump. Now I’m afraid I’m not making enough for her and I am hating being hooked up to a pump for so long.

How do I know when I should switch to formula and how do I get over feeling guilty and like I failed her?