Not quite the same situation but i swapped to FF at 2 weeks.
I started off trying to breast feed but Alexis wouldn't latch, but I kept trying for 2 weeks, while also expressing and bottle feeding (expressed milk and topping up with formula). I felt soo awful, like I was failing constantly and also hating having to pump (felt a lot like a milking cow) and I struggled to enjoy any time I spent with Alexis. I was in tears more often than not. My HV was great and suggested that moving to just FF would be best for both Alexis and I, and although it was super hard to make that decision as soon as I did (after talking to OH) I honestly felt like a weight had been lifted. I now love feeding her and feel very bonded to her (which I didn't before)
Its completely OK to move to bottle feeding if you are struggling emotionally. Your baby needs you to be happy and healthy, and if that means not breast feeding then that's OK. Also make sure you speak to your HV\GP about how you are feeling, they are there to support you.
Feel free to message me if you want.
Hugs
Em xx