You know.. I hesitate in saying to give her a soother, because I know that at her age, she is on the way of learning how to self soothe. If you haven't introduced it yet, then I wouldn't. Trust me.. it's sooo much better to have a self soother!
Right now, you are in the thick of it, with pu.pd, trying to change a habit and to top it off, you had a change in your feeding. No wonder you are feeling anxious and overwhelmed! Take a deep breath and give yourself grace.
She will adopt a new way to self soothe, you just have to give her a chance. Learning to self soothe is a gradual process.. if you let it happen, it's life long and diminishes tons of nightwakings and sleep problems later. Also, it's easier to change a habit with a younger baby than an older one. there is a huge difference in a month of development.. even week or two!
So.. if you want my opinion, hang in there and keep at it. It gradually gets easier and easier.. just have faith in your abilities and your little one's ability to learn and mature.