Are NHS right asking me to ignore meltdowns?

Good morning, 

I would really appreciate some input here, 

As some forum members maybe aware my daughter has severe sleep problems and has done for years! We finally got accepted by the specialist health visiting team who have put together a routine based plan with strict instructions on how to respond to behaviour, 

And I do understand that children will resist change and have tantrums which I'm supposed to ignore as we are "reversing learned behaviour" I have always had routine for bedtime and she is the only one of my children with a problem.

Let me describe the last few days on this plan and I would like to know if as autistic adults you believe it to be harmful, I do but maybe I'm being soft as I don't like her upset.

Day one her teachers and support worker had told her how well she was going to do following the plan (she will never disobey a teacher) she followed the plan precisely to the minute. During the night I heard her awake repeatedly saying "I must stay in bed, I must not be bad, I can't get up" this broke my heart but I did as instructed and ignored it. When she got up she was anxiously flapping her hands and crying she had wet the bed as she didn't think she could go to the toilet.

Day 2 strictly following times again spent hours during night repeating "I mustn't get out of bed" really anxious when she got up

Day 3 same as day 2

Last night followed plan got up ten mins later had tantrum I kept putting her back in bed repeating the instructed phrase "goodnight.... It's time to go to sleep" she did this for 3 hours then she got to the point of throwing the drawers out of the cabinet, hitting kicking and biting me she has hurt her foot kicking a wall, she got to a point she was literally screaming "I did the plan why are they making me. How is this helping me it's hurting me. I wish I was dead"  that really got me but did as told and put her back to bed that triggered a meltdown which I genuinely believe is totally different to a tantrum she was totally overloaded now I'm supposed to ignore that as "she will learn" I couldn't how can I be asked to ignore a child at their most vulnerable? I calmed her down and sat with her for hours until she finally got to sleep 

Update she has slept a few nights since then, well not sleeping just laying quietly in her bed repeatedly saying I must stay here I'm not bad. This feels wrong 

To me this seems cruel. And neglectful and I feel it could be very harmful to her, or am I just being to soft?