@LunaLula83 I really don't think telling a mum at her lowest ebb that she should have her child, who she certainly loves to the end of the earth underneath her grief and exhaustion, adopted out is at all helpful.
@HateLife21 first of all well done. You've got him this far, you've got him a diagnosis which will be really helpful for him. I know you are probably worn into the ground and feeling too exhausted to even seek help- is there anyone who could give you a short break?
Do you have a portage worker? If not, reach out and get a referral. There will probably be a local Parent Carer Forum/ Group who will be able to signpost you.
Look up your local Special Needs nursery and get in contact with them. They may be closed, but you could get the ball rolling to get him a place after lockdown.
It would be great to apply for an EHCP for him now. You can do it as a parent but there should also be a local Early Years SENCo who can help you. If you start now he will be able to be considered for Special School as his first placement. This will massively help you as they will support you as well as him.
Have you looked at 'Safe Space' beds? They are very expensive, but there are organisations you can apply to for funding for them. Having one might help you to get more sleep- as I imagine sleep is an issue?
So sorry you are feeling so low- it is incredibly hard and I'm sure you are doing a great job even if it doesn't feel like it. 