GYo, I really wanted to BF as have a lot of allergies myself so was really determined. I think it does help to read up about it if its something you are committed to as there is so much duff information out there.
The thing about reading up about stuff is that it means that if something is hard, you know that there's a solution out there and it doesn't have to be FF - not that there's anything wrong with FF. DS had FF, although not for first six months.
I discussed it with my MW and she advised me to start trying to manually express whilst in the shower from about 37 weeks...this meant that if I had problems (which I did) I could express and feed some to DS.
It was amazing actually, DS was screaming his head off, clearly hungry and both he and I were quite stressed. We'd been trying to get him to latch on and he just couldn't (I've got enormous norks and small nipples so it was hard work for him). A MW asked how I felt about manually expressing into a litte cup - I said fine, she got a little sterilised cup for me (like one of those medicine cups for cough syrup) and started to tell me how to do it - I said, its OK, I know how to do it, so she just watched whilst I expressed. I got about 2mm in the bottom of this thimble tiny little beaker and she said that it would be plenty! i was gobsmacked as it was such a tiny amount, but she said it was like eating extra thick whipped cream for DS. We held the cup up and he lapped it out immediately like a little cat! He then went to sleep. Job done. Stress over. Next feed was much easier.
They gave me a couple of little pre-packed sterilised cups to take home in case we had anymore problems but we didn't.
Just knowing about things like this means that when you are having problems, you know that there are solutions available - other than some MW standing next to you saying, its no good dear, you really should give him some FF to settle him down.