My oldest would never really take a bottle. At 3 months my dr's nurse recommended using a sippy cup. I used the gerber one with a very soft (rubbery) type of spout, with handles on either side that she could hold. I think it worked for her because it was nothing like breastfeeding, so she didn't feel like it was a 'fake mommy'. Also, with my second daughter, I tired several different types of nipples before one worked (she was younger so the sippy cup wasn't a good idea). I ended up using the nipple that was a gerber/nuke one like her pacifier. It was difficult to find (looks just like the orthodontic gerber pacifiers), but it fit on the cheapest bottles so that was nice.
Anyway, I wouldn't give up - just keep trying different nipples. Also, don't let this frustration force you to decide to stop breastfeeding. The first year will be over before you know it & soon your baby will be eating solids and that will give you longer periods of time you can be away from her (even if you can't find a bottle she'll take). Best Wishes & Enjoy your baby - they grow up so fast!