We transferred out of cot two weeks ago and have similar problems, only worse I think ;)
She used to sleep fairly well 8.30-6ish, maybe a bit less, maybe a bit more. 1h30 nap at nursery and similar at home (sometimes a bit more), I've been reluctant to drop nap as I am pg and often need it myself! (prob more than she does) and she gets very grumpy without it.
Since moving to bed (well, now old cot mattress on the floor) we are all over the place, one or two ok nights, but mostly terrible to get to sleep latest at 10.30, waking 4-5 times in the night and immediately crying for us, waking early, e.g. 5am.
Last night I tried sitting with her in the room every time to get her to sleep, she took 40 minutes to go off finally at 8.30, but woke at 12.30 and then 4pm, after 4pm I couldn't leave the room as she woke up every time, so she got a good night's sleep but mine was terrible.
Partly wanted to say - I share your pain/I wish I could get my DC to sleep so long, and partly wanted to hijack in case anyone has good ideas.