Trying to Breastfeed vs. Exclusively Pumping

My little one was born at 37 weeks on January 27th and ended up in the nicu with a feeding tube the next day. Our feeding journey started out with exclusively pumping and bottle feeding, but not by choice. Since he came home 5 days later, I have been struggling to get a good latch. I have flat nipples and he can't seem to open his mouth wide enough. It is extremely painful to try breastfeeding and frustrating for both of us even with the use of a nipple shield. I was wondering if anyone else exclusively pumps and what led them to that decision. Also, how long did you try breastfeeding directly before deciding to exclusively pump? We have been trying for almost 2 weeks and have seen lactation consultants for help. I don't want to give up too soon, but I feel like I'm going insane.