I dont know what im doing please help!?

have been noticing that for the past few days my baby keeps pulling her self off my and then reattaching herself or moving her head around trying to reposition her self while on the . This is happening more frequently and in less time than before. She seems to be getting very fussy during the feedings and I dont know why. I went one feeding not feeding her and supplemented her with formula, I pumped instead and only got out an ounce. When she is supplemented she drinks 3-4 ounces. I just restarted feeding her again after not feeding for almost two weeks, she was only feed for 5 days before that. So i am trying to rebuild my supply but only pump an ounce. I want to know how I can improve supply other than putting her to and pumping? Is she only getting an ounce from me at each feeding if thats all i can pump out? And why might she be getting so fussy during the feedings and repositioning herself and detaching and re latching her self? Advise PLEASE!!!!!!!!!! I really want this breastfeeding to work but im afraid im not producing enough either because after feeding for 40 min she still acts hungry after.