Which formula is good for constipation and colic?

I am feeding my newborn who is about to be two months but the milk is not filling her up completely. She wants more and more and more all the time. So, my doctor told me to supplement the feeding by adding some formula- I gave her Infamil and newborn regular kind (powder). She quickly stopped having bowel movements, the only way she would have one was with a suppository the doctor prescribed. The longest she went without a bowel movement was 5 days and she was extremely fussy and uncomfortable. So then I tried Similac Advance (concentrated)- and had the same results, constipated, uncomfortable and no bowel movements unless I added a suppository or one time I actually checked her temperature rectally and she had a bowel movement. So, I returned to the doctor and they decide to take her off the formula and strictly feed. She is now waking up every second and keeps asking for more and more. I think the milk is just not filling her up once again. I really don't know which formula to try and the doctor doesn't want me to give her any formula because of this problem, but regardless when I return to work in a couple months she will need to be put on a formula. Please HELP!!! I am DESPERATE! :(