I've not felt judged at all, but frankly I'm harder on myself as I don't want to be on formula and wanted desperately to BF. We did for awhile but I became sick and had to express (and like you found expressing didn't work for me, I just didn't get much milk from it, could express 6 hours a day and not get more than one bottle on a good day, eventually supply just dried up despite pumping). I've actually found the opposite, more people have told me how great it is that I switched to formula because 'it's easy' and 'breast milk isn't any better anyway', which frankly pisses me off. I do think breast milk is better and I don't like using formula, but in our situation, it was the only option. I know people are just trying to be nice and probably make me not feel so bad, but I wish someone would offer up some praise for the BF I did do (10 weeks) rather than talk about how little it mattered.
But regardless, it's your baby and only you know what's right for you. Your friends and family aren't going to be the ones struggling with a sleepy premie baby who has trouble latching and they aren't going to be the ones attached to a pump all day. Only you can make the decision that works for you. I did feel awkward at first pulling out a bottle to feed my baby when all my friends were BF, but they were very understanding and supportive and eventually it got to the point where it didn't feel as uncomfortable anymore. I think time helps everything so hang in there. Be thankful you were able to express as much for your baby as you did. That's wonderful!