Blimey, you must be tired.
Do you get a chance when your DH is home for a nap? (for yourself that is!)
When Natty was about 4mo we switched from rocking to patting to sleep. Quite firm pats too. Even at 3yo sometimes she'd wake at night and call me in, saying, "pat my botton, Mummy" LOL. I found that she settled for longer if she went to sleep not in my arms. She was like that though - Phoebe happily transferred (and still does transfer from the car) and slept/sleeps... for as long as she slept. Natty would definitely sleep for longer if she fell asleep in the cot though. Patting was her 'thing'.
Maybe you are still yet to discover your DD's 'thing'... Hope you find it soon.