I need some sleep.....

It is the end of the week and I'm losing my nutter!
It feels like my patience has gone, I'm yelling a lot and I haven't had a full nights sleep in over a week.
I have had a cough for about 4 weeks and it only started to get better today, I would yell or shout and my voice was go....Yesterday the coughing got to a point of me choking. Hubby was great and came home and looked after the kids so I got a break. In between them coming to check on me and seeing what I was doing.
Yesterday was a very long day with 2 appointments in the morning and school and kindy. So today I was looking forward to meeting some new people and letting A have a play in the park.
This time it was L who was the problem.
Miss A was great and didn't run away and had a good play but Miss L was cranky and tired and hadn't slept by 11am. I gave her a bottle and changed her nappy then everyone arrived. We sat down to talk and play but L was still upset and crying. It didn't matter if I held her or rocked her she would not settle. By 1pm it was time to go, my patience was running thin.
On the way home both girls slept but when the car stopped L woke up. By this stage it was 1:30pm and she had had less than 30mins sleep all day.
I put her to bed and 5 minutes later A woke up. We had quiet TV time while I tried to switch of. By 2:30pm I had given L Panadol to help the teething and she slept. 5 minutes later I put her in the car to drive to school :(
Of course she didn't stay asleep.
At this point I was overtired and could have used a nap myself. It was getting warm and making me sleepy not a good combo while driving!
When we got home from school A was hyped up as she loves playing with the big kids at school and L was crying again.
Now it's 4pm and she has finally gone to sleep.
I am hanging on for hubby to get home then I am crashing. Mentally and emotionally I am done for.
I need a night of uninterrupted sleep. Last night it was A at 3am crying for me, asking me to put her to bed. Daddy wouldn't do it was me or nothing.
Why is it always between midnight and 4am? Right when I am in my deepest sleep? Why can't Daddy do it?
Why does she wake up at all?
I can't wait for the sleep study to be done to give us some answers.
In the meantime I will keep dreaming of a full nights sleep.....