habit forming

oh dear, we might be creating another bad habit that will need to be broken with tantrums and heartache in the future.
for the past three nites percy has ended up in our bed for the majority of the nite. she has woken up variously between 8pm and 10:30pm and not gone back to sleep. for instance, last nite (sunday 27th - her 16th month anniversary), she woke at 9:20pm with a little whimper and cry. she seemed to settle herself with a few noises that i hoped were done in her sleep. however at 10:20pm she woke properly to cry in ernest. i got up to warm her milk bottle hoping some warm milk would send her back to sleep. she took approximately 150mls, rolled on her tummy, was quiet and then i stepped away from the cot. up came her head, then up on her arms and a plaintive wail. great. i tried to shush her, rubbing her back and encouraging her to lie down again. not to be. i picked her up and she settled quietly against my shoulder. trying to put her back in her cot after a few minutes just resulted in her wailing and kneeling up again. at 11pm paul took over. for 25 minutes he tried to shush her... calm her. to no avail, she screamed blue murder, sobbing out "mamma, mamma, mamma" so hard she choked and coughed, nearly to the point of vomiting i think. i couldn't take it any more and i'm sure paul was at his wits end. i took over again. as soon as she was against my shoulder she was quiet. i don't resent her, i don't rail against her. i just hate the situation.
i pulled some blankets out of the cupboard and lay on her bedroom floor with her. she was quiet but not sleeping. after an hour and half of this i was too cold and too uncomfortable to continue. back in her cot she went, up started the wailing and screaming.
conceding failure i carried her into our room to settle her between us in our bed. oh dear, third night running... what are we doing to ourselves?
she was quiet eventually, sleeping herself, allowing us too to get some sleep but it was poor and broken. i was looking at the clock every hour. oh god. this can't continue, i'm really tired and dreading tonite.
what can we do? leave her to scream herself to exhaustion? this could take hours- i know i couldn't take it. i wish she could talk and explain to us what is bothering her. is she lonely? frightened? perhaps then we could discuss it and sort it out.

i know people co-sleep with their children for years. and we did when she was new-born and while travelling overseas. it won't work for us long term tho. she needs to happily sleep in her own bed, all thru the nite. i'm just depressed about the whole parenthood gig. a friend of mine is leaving tomorrow for a yoga retreat in thailand for five weeks- christ i wish i could climb in his suitcase.