Fussy feeds/teething??

Hi guys - wondering if anyone else having the same issue. My 5m old is teething (we think). Last few weeks has been very fussy, drooly and chompy and gums now look red and bumpy. Last couple of days she has been biting the bottle teat at every feed, very uninterested in drinking milk and drinking pretty small volumes (2-3oz) and not at all finishing her bottle (she has never been a big eater anyway - max I can get her to drink in one go is maybe 5-6oz and this is on a good day.) Still having wet/ dirty nappies and otherwise is generally happy and seems well in herself. We use MAM bottles teat size 2 at present. I tried the 3s but she’s still chomping and drinking small volumes with those and perhaps getting more upset with them too, so I don’t think teat size is the issue. Can teething affect feeds this much? Would giving some pain relief before feeds make a difference or do I just let it pass and trust that she will catch up in a few days time when she feels up to it? Just needing some reassurance!