EBF baby won’t take a bottle, please help!

Hi guys, I know some of you struggled with this too so I’m looking for some advice.

I’m exclusively breastfeeding my daughter since birth and I’m still on maternity leave so I really didn’t have any reasons to give her a bottle during these past 5 months.

My husband gave her a bottle here and there if I was away and it went well, but it wasn’t very often. We used Avent Natural glass bottles.

When my daughter was 3 months old our pediatrician advised us to start giving her a bottle every couple of days so she would get used to it, as I am going back to work in October. We started at the beginning of the summer and she went from taking a bottle just fine to refusing it and throwing a fit (as in she cries hysterically, spits out all the milk and chokes). By the way, I always give her freshly expressed breasts milk so there is no reason for her to refuse it other than the fact that it’s in a bottle.

She starts day care on September 30th and I’m freaking out. We tried pretty much everything. Lots of different bottles, different nipples, I tried giving the bottle, other people have tried to feed her while I was away, we also tried different kinds of pacifiers (she recently stopped taking pacifiers too 😱), tried feeding her when he was very hungry or when she wasn’t too hungry, tried giving her the bottle to play with... I really don’t know what to do.

My only hope now is a sippy cup as I know it worked for my niece who also wouldn’t take a bottle. I’m going to try this next (if you have sippy cup recommendations send them my way please!).

If anyone has any tips I’d be really grateful, I’m so worried 😔