well, call me in the middle (lol- to the clw mamas, i'm the cruel beeotch who forced her 7 yr old to wean; to, er, the rest of the western world, i'm the crazy beeotch who NURSED TILL 7... atm, my 2 & nearly 4 yr olds are happily still snacking, & i have no plans to end their reverie.)
there have been many times i have thought 'oh JEEZ, i am hating this; surely it will damage them irrepairably to be nursed with resentment', but i've kept in mind that it is a feeling, and feelings change- weaning is forever. i don't adore my dh every second of every day, but i don't divorce him when i am pissed i tripped over his shoes left on the living room floor.
for every time i've thought, 'c'mon, baby, my shoulder aches. and stop twiddling!' there have been a dozen times i've been incredibly grateful we're still nursing- when they've been sick and would otherwise have been hospitalized from dehydration, when we've been upset with each other and found a cozy way to reconnect, when they can't sleep and are sad or lonely, etc.
can you, without resorting to the forever step of weaning (nak, hard to type!), make adjustments to your relationship so it's not so hellish for you? (your feelings count, too!) gradually moving them out of my bed, to a cosleeper, then crib beside my bed, to crib in other room, and now their big boy beds (of course, they still nurse to sleep and wake, and baby likes me to get him at about 4 am and snuggle for a couple hours) has enabled me to get the sleep i wouldn't have, if i was next to them smelling my milk (i know from experience they would definately suck all night.) family bed compromises have kept us nursing... would you really want to wean, if sleep and sore shoulder issues could be resolved? 21 months is still such a baby....
anyway, good luck, and good sleep. suse
