I had this same issue with my first boy, and just discovered this helpful article: http://www.sleepywrap.com/Breastfeeding/25pdf.pdf.
My personal experience is that trying to introduce the bottle this late is a waste of time. My 8.5 month daughter takes a straw sippy cup great and she won't take a bottle -- so try to spend more time with the straw (it is also better for proper jaw & palate development anyway).
When you try to breastfeed, go to a quiet room. If she pulls off, wait to see if she comes back to the breast on her own in the next 2-3 minutes. Relax and take your time.
I like these suggestions from kellymom.com:
Make sure that baby is nursing efficiently. This is the "remove more milk" part of increasing milk production. If milk is not effectively removed from the breast, then mom's milk supply decreases. If positioning and latch are "off" then baby is probably not transferring milk efficiently. A sleepy baby, use of nipple shields or various health or anatomical problems in baby can also interfere with baby's ability to transfer milk. For a baby who is not nursing efficiently, trying to adequately empty milk from the breast is like trying to empty a swimming pool through a drinking straw - it can take forever. Inefficient milk transfer can lead to baby not getting enough milk or needing to nurse almost constantly to get enough milk. If baby is not transferring milk well, then it is important for mom to express milk after and/or between nursings to maintain milk supply while the breastfeeding problems are being addressed.
Nurse frequently, and for as long as your baby is actively nursing. Remember - you want to remove more milk from the breasts and do this frequently. If baby is having weight gain problems, aim to nurse at least every 1.5-2 hours during the day and at least every 3 hours at night.
Take a nursing vacation. Take baby to bed with you for 2-3 days, and do nothing but nurse (frequently!) and rest (well, you can eat too!).
Offer both sides at each feeding. Let baby finish the first side, then offer the second side.
Switch nurse. Switch sides 3 or more times during each feeding, every time that baby falls asleep, switches to "comfort" sucking, or loses interest. Use each side at least twice per feeding. Use breast compression to keep baby feeding longer. For good instructions on how to do this, see Dr. Jack Newman's Protocol to increase intake of breastmilk by the baby. This can be particularly helpful for sleepy or distractible babies.
Avoid pacifiers and bottles. All of baby's sucking needs should be met at the breast (see above). If a temporary supplement is medically required, it can be given with a nursing supplementer or by spoon, cup or dropper (see Alternative Feeding Methods).
Give baby only breastmilk. Avoid all solids, water, and formula if baby is younger than six months, and consider decreasing solids if baby is older. If you are using more than a few ounces of formula per day, wean from the supplements gradually to "challenge" your breasts to produce more milk.
Take care of mom. Rest. Sleep when baby sleeps. Relax. Drink liquids to thirst (don't force liquids - drinking extra water does not increase supply), and eat a reasonably well-balanced diet.
Consider pumping. Adding pumping sessions after or between nursing sessions can be very helpful - pumping is very important when baby is not nursing efficiently or frequently enough, and can speed things up in all situations. Your aim in pumping is to remove more milk from the breasts and/or to increase frequency of breast emptying. When pumping to increase milk supply, to ensure that the pump removes an optimum amount of milk from the breast, keep pumping for 2-5 minutes after the last drops of milk. However, adding even a short pumping session (increasing frequency but perhaps not removing milk thoroughly) is helpful.
Consider a galactagogue. A substance (herb, prescription medication, etc.) that increases milk supply is called a galactagogue. See What is a galactagogue? Do I need one? for more information.
And this kellymom link contains an article "How might I increase baby's weight gain?" http://www.kellymom.com/babyconcerns/growth/weight-gain_i...