21 month old possible autism and no sleep - help please!

[TinyDancer275]

Hello,
I thought I would post on here as I have noticed a few signs that my DD has maybe possible autism. I am very new to this so don’t know that much about it , so please hear with me!

She head bangs a lot in the day when she’s frustrated / angry. Against stone steps, floors, ceramic sink - anything she can bang against.
I’ve read it’s a self soothing mechanism and told by doctors it’s fine.
She head bangs at night which is awful to be honest. She is awake every night 4 hours at least, last night it was 11-5!!
Just crying, banging.
I went in to comfort her but obviously don’t really fit very well in the cot.
As soon as I went, screaming again.
I’m at my wits end, I can’t see a way out, I’m praying will get better but to be honest I’m struggling to survive on 2 hours sleep a night. I also have another daughter who’s 6.
I dont know if my child has autism, but read a lot and sleep disruptions / disorders comes up a lot. Have you got any tips on how to cope with this? Should I get a single bed with bed guards all the way round and co sleep when it gets bad?
She also does the repetitive hand movements , is obsessed by bottles / tubes rather than toys.
She only says 2 things as has repeated them for months.
She understands almost everything I say though. She also follows my gaze and points to things
Regarding sleep, she generally has a 2 hour nap in the day and sleeps very well for it. Would you recommend shortening it?
Thank you so much for any replies xx I
Just feel quite out of my depth here x

Could you ditch the cot and just have a mattress on the floor? Or are you worried about her moving around in the night? I did a lot of co-sleeping with ds when he wouldn't settle at night and once he fell asleep I would extricate myself and go back to bed. It was exhausting and thankfully he sleeps much better now he takes melatonin.

My son used to head bang a lot and was eventually diagnosed with a sensory processing disorder as well as ASD. Have you heard about sensory diets (a series of exercises that you do throughout the day to keep your child regulated), the out of sync child is a good book to start with. My son used to find deep pressure and stretching arms and legs helpful and calming in the evening.

Some people swear by weighted blankets but they can be hit and miss. Ds loves his sometimes and other times he finds it completely overwhelming.

I never used to stop ds napping in the day as it was the only time I had to myself without having to constantly watch him!

Could you try her in bed with you?

Hi, thank you so much for your replies
Yes, I haven’t really put her in my bed, just because the few times I have, she’s got really upset as she’s wanted to get out and play
And I haven’t got any bed guards on / blackout blinds in my room but think going to get some just in case
I wasn’t really wanting to
Co sleep as my partner and I are in separate beds just so he can get some sleep and my thinking was if I started putting her in my bed then we will never get back to sleeping together
But - if it means she would sleep , then it would far outweigh anything else
Thing is she’s always settled on her own in her own cot so she’s never been rocked to sleep, slept on me, apart from when she was tiny
I thought about the mattress on the floor, but yes, I’m worried I might just make everything worse with her moving about and going out
I’m feeling really desperate
My partner isn’t really supportive emotionally and doesn’t like the noise / crying / head banging so it really is up to me to try resolve it
I know not ideal
But it’s just the way it is x