3 year old getting overtired and waking

Hi,

my 3 year old daughter (who has ASD, but so far quite high functioning) has recently become very difficult to put to bed in the evening and even though she ends up dropping off at about 10 pm, still wakes up at 2-3am, very distressed.

When attempting to get her to into bed, she throws big tantrums (and screams, crys, flings herself on the floor, etc.) even though to look at her, she looks absolutely shattered.  She knows what the word 'No' means and says it regularly when we ask her to go to bed. 

This is a nightly battle and is bad enough.. but also she tends to wake up in the middle of the night, very distressed and unconsolable, almost as if she is in a strange place, surrounded by strange people.  We cant talk to her, or touch her without her screaming and flinging herself on the floor (which can be quite dangerous), she'll then stay awake for an hour or two before dropping off again.

I've read a bit about melatonin deficiency and possible night terrors, etc. but I was wondering if there was anyone who has any similar experience (with a simliar age child) and any ideas for how to approach dealing with it.

I think she is too young for the use of warnings or timeouts as she wont really understand the concepts yet.

This is generally causing quite a lot of disruption to our household and family and puts everyone on edge.  I'd be very interested to hear about anyone's experiences in this area and any success with dealing with it.

Many thanks