Zimm, huge sympathy, and I absolutely recognise your description. Oh yeah. DISCLAIMER - DS is now 8 weeks old, and things are a lot easier compared to 4 weeks (I know you know it gets better etc etc).
Like others on this thread, I didn't have any real problems or issues - I just had to deal with the reality of BF-ing (no one else can feed except you, prisoner-on-the-sofa syndrome, cluster feeding hell, feeling huge sense of relief when I could leave DS with someone else for 5 minutes and get away - and so on. Oh, and all that 'but isn't it WONDERFUL! How BONDING for you! rhetoric from BF-ing Pollyannnas drove me round the bend. It didn't feel wonderful or bonding. It was exhausting and very demanding).
BF-ing in the early weeks really was very, very taxing - in ways that I certainly wasn't prepared for. Despite the tidal wave of pro-BF-ing material that came my way via MWs and Health Visitors.
As far as the 'you don't have to' response goes - well, of course you don't have to. Me neither. BF-ing is a choice [for the vast majority of us - I know there are women who physically can't]. Breast milk is better for a baby than formula. That's why I'm choosing to BF. I do ask myself quite often if it is 'worth it' - and so far the answer has been 'yes.'
If I felt I was genuinely going to have a nervous breakdown because of BF, if I had PND and the sheer demand of BF-ing was a contributing factor - then yes, I would turn to formula. Some mums do end up in this situation, and it is a solution for them.
But I'm not in that position. I get very frustrated with the personal limitations that BF-ing puts on me - but for me, atm, setting that against the long term benefits that BF-ing will give my son makes me carry on. I would love more sleep - it would be fab to go out and get hammered one night - I'm dying to take up serious running again - I would love more of a break from DS than BF-ing will allow a lot of the time. And all the rest.
BUT then I think - it really is only a few months we're talking about. I owe him that much. It is a lot easier now than the first few weeks. I don't imagine I'll ever LOVE breastfeeding like some women seem to, although who knows (and venting about it is a big help) - but that's okay. Unfortunately, as parents, we don't only get to do the bits of parenting we absolutely love. Darn it.
So rant away - I find it very therapeutic to read about other people's frustration!