Hi,

You do sound exhausted and "over it"
Remember, at any point you can pull the pin on breastfeeding. She's 8 mnths old. You have done an amazing job with her - you don't have to keep going. What were your personal goals for breastfeeding.
Having said that, this isn't *the fault* of you breastfeeding her. A quick perusal of the sleep forums will demonstrate that many bottle feeding mums are up and down all night making bottles for their little ones - still getting no sleep.
At 8mnths old you would be hard pressed to smother her! I don't think she'd stand for that. You'd hear about it! If she wakes up that often, she won't smother very easily.
Does she have a dummy? Babies have a huge need to suck. Maybe if she is using you as a dummy, then a dummy is what she needs. It can take some practise, but she may take it with time, during the night when she is asleep. Many mums get more sleep co-sleeping. At least you can stay horizontal and you are able to get back to sleep more quickly. Does she has a ruggy, teddy or pillow? Might be time to introduce one. Not necessarily a quick fix, but babies will often suck on these items or snuggle them to their face to comfort themselves back to sleep