entropy, sorry you had a bad day yesterday, it's hard isn't it. Do contact a breastfeeding support group if you can, and if someone could check your latch that would probably help too.
I know how wearing it is to be constantly feeding like this - all 3 of my babies have lost lots of weight and then regained ever so slowly. Ds2 lost over a pound at birth, and on the centile charts has gone from 99.8th centile at birth to 2nd-9th centile at age 4 months. But I'm sure all is well. BUT, it took a lot of work and heartache to get him feeding properly - what I did was to feed every 2 hours, but to supplement with expressed milk. I'm not necessarily recommending this, as it is a total pain to do, but my problem seemed to be lack of milk.
My routine was, immediately prior to a feed, express from one side, plus a little from the side I was going to feed from (in theory this makes the milk more calorie-rich and less watery - don't know if this is true or not...), then feed him from the side I'd expressed a little from. Then feed from the other side, if still interested keep switching, then only when not interested in the breast anymore, give him the 'top up' EBM. He would then be quite settled, so I would take that opportunity to wash and sterilise the breast pump and bottle, ready for the next feed.
To be honest I did wonder why I was doing it, and it did feel terribly alien to the 'breast feeding is so easy, you just feed them' mantra. BUT after about 3-4 weeks, he was feeding with no EBM, and his weight started creeping up. He's still a thin baby, but he's meeting all his milestones, so I@m not overly concerned. Having said that, he only weighs 5.95kg having been born at 4.58k.
Do hang in there - you'll get loads of support here. Don't try and do anything else except feed him - it doesn't matter if the house is messy or if you don't go out - just stay with your baby and feed whenever you can!