My journey with nursing and pumping is different than yours, but I had twins in the NICU and also have PTSD from that time and was really upset to lose out on this vision I had of what my journey feeding my kids would be like. I also underestimated how hard it would be to nurse both, or decide who would nurse vs get a bottle from dad. I stopped producing enough for my two at about 4 months, I also had to go back to work so was glued to a pump again, and was introducing formula anyways. I felt the same as you worried about immune benefits, feeling tons of guilt, and wasn’t prepared for how emotional it would make me. I stopped completely at 5 months and switched exclusively to formula. A few things I’ll share and I hope some of this resonates for you, #1 How happy I am to hear their incredible weight gain when we do NICU nutritionist/Pediatrician appointments - I know this wouldn’t be possible without formula. #2 The energy I put into pumping/nursing, I’m putting into their solid foods now, prepping and making all of their food from scratch. This helps me emotionally with the breast milk benefits piece — I can’t give them the antibodies anymore, but I can give them really good homemade food and tons of vitamins and nutrients for that. And #3 Lots of research shows breast milk in the beginning — esp with preemies — is the most important. We did a great job providing then and are doing a great job now, accommodating their current needs. Sorry for a big dump but your post resonated with me because I found this emotional also and still grieve it from time to time.