Should stop breastfeeding?

I started my pregnancy assuming I would be able to breastfeed, or at least pump, rather easily. I was wrong, on so many levels. The hospital I went to had a great deal of conflicting advice and was next to no help when my daughter continued to have problems latching and a super short fuse for patience. The nipple guard became more of a hindrance than a help, a hassle to put on and prone to popping off at the slightest provocation. I'm of a rather large build as well so holds and positions were difficult and awkward, with neither of my family members who had breastfed being much help since they are rather tiny and thin with small breasts. The only times I managed a good latch were with the nipple shield and trying again the same day met with frustration and shame. I was left to pump, which was a full-time job in its own and I barely did enough for a feed. Then we found out she was allergic to cow's milk and soybean products, so I had to change my diet completely and go for the super expensive hypoallergenic formula for supplementingb which had long since stopped being just supplementing and was now her main food. As time went on, my husband started to lose the will to support me in trying to breastfeed so I now only get to pump every so often and he is never around when I want help to get her on the breast. So I'm asking now, with four long hard months of trying, if I should just go straight to formula.