DD is 8m tomorrow and her sleep is going from bad to worse. A few weeks ago we had a few blissful nights with only 1 waking for a feed, now we are back to at least 3 wakings, but that's not the worst part...
She is going down no problem (or minimal problems) at bedtime and will sleep for about 2-3 hrs, but she then wakes up and stays awake for mammoth periods and just will not go back to sleep. This has been going on for 2 weeks now and I can't cope. It can (and has done for the last 2 nights) go on for up to 3.5hrs no matter what I do
. Sometimes she appears to have gone back to sleep and just when I get back into bed, she starts all over again 
Last night DH insisted suggested that we let her cry a bit. He wanted to let her cry it out, but I was only happy to do 'return and check' or whatever you call it, it still involved listening to her crying/yelling/screaming which I didn't really want to do, but tried as a last resort for some chance of a decent sleep.
Every time I went it she was up on her arms and had turned herself around in the cot and 1.5 hrs later and she was still going at it.
I picked her up to put her back into position in the cot she clung to me like never before, like she was really very distressed/upset - which made me think that this just wasn't the approach to take...so I gave in and fed her (it was time for a feed by then anyway).
DH then just left me to it as he had to be up early, so he took himself off to the spare room and closed the door
while I dealt with her. She did go back to sleep afterwards with a bit of patting, but had probably worn herself out anyway with all the crying.
Has anyone got any suggestions as I can't cope with another night of this. I am tired and tearful all the time. DH is sick of me going on about DD's sleep issues (even tho the CC didn't work, thinks it was the right way to go). We are bickering/arguing all the time and it's causing a real problem in our relationship. 
Can anyone help??? Please???