Sleep training a baby that young is detrimental IMO. It's been proven to be bad for their little brains let alone feeding etc. Even Ferber has come out to say he was wrong. That babies shouldn't be self settled or made CIO at all.

I know how frustrating it is. But I would look more into reading cues. Also reflux and gas is the biggest cause of an unsettled baby. And leaving them to settle on their own is not really helping that at all. Try and remember this is all normal. Babies don't sleep like adults. They have more frequent needs than we do.

And the one thing I want to absolutely swear to you... You cannot spoil a baby. By cuddling them to sleep. Or settling them with you in a cot it is not going to spoil them or create some pattern that you can't undo. It just doesn't happen. Babies routines and needs change a billion times over the first year. And right now she needs comfort and reassurance. Not to be self settled. As at this age she is wired to think she is abandoned if left. It's like an inbuilt protective mechanism so that they don't get left because they are pretty helpless.

You are doing a great job! Keep talking! And keep at it. But just remember this is all normal. And you can do this!
I completely agree with Rouge.
Sleep deprivation is exhausting and really tough but as parents it is up to us to adjust to it, rather than trying to enforce our belief of the amount of sleep we think is normal on them. Our norm is not the norm for a baby. Good luck.