Need some help regarding sleep

[Memeto3boys]

I have a 2 year old with very clear development delay which professionals are saying us due to asd. Which I agree with its definately presents has autism.
He's always been such a fantastic sleeper never had the sleep regressions when he was a baby never suffered with separation anxiety or any of the things baby's generally go though. We put him into a toddler bed at 15 months old and never had a problem he never got out just slept. Last Tuesday for some reason he decided to be total opposite refuse to stay in bed is up and down though out the night. On first thought I thought it was change due to Christmas decorations and hype for Christmas but now looking at the whole picture it seems to be about me he hates being away from me. He's also started being very angry when people coming near me even his brothers and has become totally obsessed about me just being his meme and no one else's. Now I know this is normal if not a bit older than usual for a child to go though. I am just wondering how I handle it. It's taking me up to 2 hours to get him to bed which is proving difficult as I have a 1 year old too and have to do night time routines on my own as Dh works from 11.30 am till 11pm 5 days a week which makes it difficult trying to establish a routine. I can't just leave him to cry as he will cry till he's sick and he then keeps ds3 up. I have tried put him down first but I have no one to watch ds3 while I deal with him for so long. I can't just put ds3 to bed as he isn't and never has been a good sleeper and needs to be pushed in his pram to sleep. I know that this probably all sounds so a mess but I have to do what I can juggling them best way I can. I have been reminded on several occasions by HV that I am making a rod for my own back but what do I do when ones only 1 and still learning and my 2 year old struggles a great deal with understanding. I have tried rewarding him sleep training he just understand the process.