Sounds like my DS at a week old (he's 4 weeks old now, and things have got a bit better!) -
What I learnt was: -
There's a growth spurt at 7-10 days, which involved near constant feeding for us. Epic cluster feeds in the evening where like you, I wondered when I had time to go for a pee, let alone anything else. I found it exhausting, demoralising and depressing - and I have none of the grim problems some other mums seem to have with BF-ing, gawd knows how they cope.
No one encouraging me to BF when pregnant warned me about this, btw - so I also worried there was something wrong with my supply, or my baby. I've also found talking to friends who started out BF-ing but then fed formula early on that they 1st introduced bottles round about 1 week - I think partly out of exhaustion, but largely out of fear and worry that their baby was starving. They feed so much and seem so fussy/unhappy, and you can't tell how much they are getting, if any. Etc.
It did pass! And it is just a baby's way of 'ordering' an increase in supply. Which kicked in after 2 days of just crazy constant feeding for us, and then it all calmed down a bit.
It didn't help that my DS didn't sleep for more than 2 hours at a time, when he actually slept (talk of 1 week old babies who apparently slept for 4-5 hours just made me jealous and resentful). And being told to go for a walk made me cry - I could barely get time for a poo, let alone a poo/quick shower/time to get dressed/get baby dressed/into buggy and out of the front door. ALso being told to 'enjoy it' made me feel very inadequate at the time, and like a horrible mum. I didn't enjoy it - I just toughed it out, and I'm afraid that was the best I could do! But I'm still BF-ing at 4 weeks and counting, and baby is doing well, so frankly, that's fine.
So, erm - I have no advice, just lots of sympathy. I really think the 7-10 day growth spurt and cluster feeding is a killer - you're still knackered from birth, but you feel like you should be getting on top of things a little, etc. It's one of nature's bad jokes, IMO! But it does end, so if you can Endure and Survive this bit, you are doing brilliantly, and you can go to the toilet with some degree of dawdling at 4 weeks...!