i've just read the OP.
YANBu, not at all, but you mustn't do that .it is reasonable to feel like that, but you just cannot act on it.
best advice HV ever gave me, in among a whole heap of uteer uselessness, was if the baby gets too much, put him in his cot, gently, place him in, put the sides up so he is safe, shut the door, and do something that occupies you for 10 mins - the washing up, hoover, the washing, check your emails, something that is a task which has a natural end, and say to yourself, I will not go back in until I ahev finished the washing up or whatever, and then finish the task, and my ds was often asleep by then, in which case - GO TO SLEEP YOURSELF - drop everything, and sleep, everything is more awful when you are exhausted, or if they are still awake and shouting, at least you have had a little break, you can go back in, check ok, then do something else.
a good cry never harmed anyone, but being shouted at by their mum, well that might be differnet.
but yes, ylu are totally totally normal, i felt like that often hence my reciving the advice at all from the HV.
good luck.