Hello poppet
You are doing brilliantly.
Two things really jumped out - he is attached to you - he’s telling you this when he follows you round and requires you to watch TV with him. But he’s also not secure in that so he can’t let you go or your attention wander.
I’d expect that to get better in time but in the meantime, you could try a couple of things; Firstly make sure you take any opportunities you can to seek him out for cuddles and attention and fun. So any moment you get when he’s with you DH or distracted in a paddling pool or whatever, you go to him for a cuddle or hair tousle. Show him that you need him too. Secondly, talk through with him what he can expect. ‘Okay, I’ll watch one episode of Blaze with you, then I’ll stay here and read my messages and keep cuddling you, but then I need to go make tea. After tea we can have more cuddles and you can come and keep me company in the kitchen.’ (I used to take photos of sleeping DC to show them ‘how cute they were’. I just wanted them to know I’d still been there at night.)
The other thing was to get a routine. Anything. It’ll help you as much as him. Do whatever suits you, but do the same(ish) thing every day. Up, breakfast, play, walk, messy play, lunch, garden, tv, tea, bath, story bed. (I know with a three year old that list gets you to around 10am but you get my drift...)
In the first instance I’d assume it’s delayed terrible twos (and also anything that looks like asd is more likely to be trauma-related) rather than anything else. Doesn’t make it easier to live with...
💐