My lg was probably about the same age and, as you say, even though she had no teeth it really hurt! We also had lots of issues with pulling on and off, pinching, hair pulling etc. It was not a fun time
I started to get quite disheartened and for a while didnt enjoy feeding her - it even felt a bit like she didn't like me any more! A few things realIy helped:
Talking to other bf mums and realising I wasn't the only one and it didn't mean my baby didn't like me!
Waiting for lo to be hungry before feedngs and taking her off once she was finished properly feeding. Apparently babies won't bite when they are feeding properly so it usually happens at the end of a feed when baby has had enough.
Feeding baby in a darkened, quiet room. This helped for 2 reasons - firstly there was less for baby to be distratcted by which helped stop the on/off business and also it means lo had my full attention - babies also sometimes bite for attention.
Feeding lo when she was sleepy. Combined with the darkened room this means I usually feed lo before naps. Im quite happy to feed lo to sleep but if youre not then feeding when theyve just woken up can also be good.
Getting a nursing/fiddle necklace to keep lo focused and her hands busy duri ng feeds. Stops the pinching, hair pulling etc. I bought a gumigem but they are really pricey and I've since discovered that you can get some really pretty ones on etsy and facebook far cheaper. This also helps with the pulling on and off as it encourages lo to focus on something close to you so they can get on and nurse. Helps when feding out and about too.
Giving plenty of other things for lo to chew/mouth/teeth on during the day. As well as the usual teething rings and toys you can give things like breastmilk lolipops (really!) which as well as being lovely and cool on the gums (great for soothing teething pains) also helps up their bm intake if they are not feeding so well at other times (https://www.breastfeeding-problems.com/breast-milk-lollies.html)
When lo does bite then try not to over react as this may be frightening but equally don't sit there stony faced as you need lo to realise its not ok. Taking them off for a minute or two really helps but it can take a while. Your lo was clearly confused when you did this, it will take her a while to work out that it was because she bit and that biting=no boobies! Persevere, every mum I've spoken to said their baby got the messgae in the end! If lo won't let go, then the advice I was given was to pull her head in close - this is uncomfortable and a bit hard to breathe easily so they let go (Dr Sears recommends this in 'The baby book' and it s not as cruel as it sounds!)
Good luck! x