I started breastfeeding my first baby but had a lot of problems with thrush and basically two weeks in she was getting so distressed I started expressing and feeding her from the boob where I could, I was determined I didn't want to use formula if I could express so I carried on. Long story but no one diagnosed the thrush until 8 weeks and by that point she was having expressed milk at almost every feed. The only feeds she wouldn't have a bottle was night time because it was like she didn't notice the taste or whatever it was that was bothering her about the thrush at those times. But at 10 weeks she did her last night feed (I know I was very lucky to have had a breast fed baby slee through from 10 weeks! I've since had one that never sleeps through). So I exclusively expressed for 8 months then switched to formula as I was pregnant with my second baby by that point and my milk dried up.
Second baby would not take a bottle - later turned out it was because he had an undiagnosed lip tie which didn't relax enough until he was 9 months and that's when he took a bottle and I switched to formula at that point. This meant that I had to throw away about 600oz of frozen expressed milk because it went out of date and he would never take it. If you express you'll know how devastating that would be!
Expressing for me was horrible, I was so determined I did it anyway but sometimes I would he sat in tears doing it because I too am not a massive fan of my nipples being touched, they are a bit hyper sensitive. I never get like that when I breastfeed though so it's weird. My one tip for any pain when expressing would be to put some lansinoh nipple cream on before you express as it stops some of the friction between you and the pump and is totally safe for a baby so doesn't matter that obviously tiny amounts would get into expressed milk x
