I think you just learn to function as you have too, I have had teary days, snappy days etc. DS1 didnt sleep thru the night till 11 months old (was BF to sleep) even then he wasnt settling for final time till 2300 ish then sleeping till 0800. During days he would BF to sleep and only sleep on my knee or in pram, 11 months stopped sleeping in pram grrr and 13 months I could put him down during day in cot!!

DS2 generally awake 2300 - 0001 until 0100 or 0200 then awake again at 0500 ish into bed with us until 0800 when DS1 wakes up.

Some days I am so tired I dont know how I get thru the day.

Hugs it will pass we will all get sleep eventually. (DH does not cope well if he does not get a good sleep.)