@allfree15 Ah, I understand. Yes, it's definitely harder when they won't take a pacifier in my opinion.
Babies have shorter sleep cycles than adults, and often have trouble connecting those sleep cycles. The reality is almost no baby (or adult) truly sleeps through the night, we just connect our sleep cycles and go right back to sleep.
When she wakes, does she immediately start crying? We do not do CIO, but we will do fuss it out. If baby wakes and starts fussing, we let him be. Most of the time he goes back to sleep. When he starts actually crying, we get up and tend to him, usually he's hungry. I used to jump up and get him every time he made the smallest fuss, and I wasn't even giving him a chance to get back to sleep on his own! Not sure if that's relevant to you, just something to think about.
If she was just fed, and you know she isn't hungry, then I wouldn't feed her. Do you have a partner, someone without breasts that smell of milk, who can go in and try soothing? Or who could take over the bedtime routine after you're done nursing?
I personally don't think that feeding to sleep is an issue at all, BUT when babies can smell the milk, they want the milk, even if they aren't really hungry! Your baby also finds nursing soothing. She's using you as a pacifier. Which is normal, but only okay when it's okay with you. Personally I would keep trying on the pacifiers... I know it's easier said than done, but a pacifier was a complete game changer for us. Luckily we started pretty early so we only had to try a few different brands before we found one he liked (tomme tippe).
If she doesn't like being rocked to sleep, there's probably something else she likes that would help her sleep. We've gone through phases of how we get our son to sleep. Sometimes we would have to stand and essentially sway him back and forth, bounce him, just lay with him, and now rocking. As annoying as it is sometimes that's our job, to find out what it is that works!
You'll also see that a pretty common opinion in this sub is that sleep regressions are not real. It's not just a natural thing that happens to all babies, and they're not based in science. Sleep regressions are more likely to be developmental changes that parents simply haven't adapted to yet. At 3.5 months when you said all this began, she was just leaving the newborn phase. Going from a sleepy potato to a baby. Lots of changes! And with those changes often come changes in parenting. Changes in feeding schedule, wake windows, nap times, preferences, etc. So I personally wouldn't focus too much on the sleep regression and focus more on following her cues and supporting her development.