Oh how I know exactly what you are going thru! I have an 8 wk old and just dealt with the same thing. My doctor ad me start giving our daughter one bottle a day around 3 wks, as long as she was nursing well. I'm still strictly nursing her but my husband gives her one bottle of pumped milk a day. That way we are sure that she will take a bottle allowing us some freedom later.
As for the pumping, I know it's frustrating so hang in there. In the mornings when I had the most milk, I personally would let her nurse on one side and pump on the other. After that I would pump both sides right after I nursed her until it was empty and then for another few minutes for the stimulation to help make more quicker.
I worried about not having enough and only pumped a little as well so I began taking fenugreek, and blessed thistle. I also tried Mother's Milk, however it made my daughter spit up so I stopped that one after 2 days. Those herbs help in encouraging lactation which has been helpful. I currently make enough to feed my daughter and her to grow well but not enough to save and store much for her. I eventually had domperidone prescribed from my dr to help the milk supply. Now everything is great!
Also, watch this video about "maximizing milk production." Kinda odd, but very helpful!
http://newborns.stanford.edu/Breastfeeding/HandExpression...
Let me know if you have any other questions! Hang in there!!