Mum who has done everything for her sin since childhood

My partner has basically done everything for her son since childhood. He's almost 28 and the only thing he can do without prompting is make his tea, putting it into the oven.

He's autistic, ADHD and has learning disabilities, depression and severe anxiety issues. He has said in the past "why should I" and I'm lazy, so what, he practically begs his mum to do things for him. I'm really getting to the end of my tether with the situation at home. He lies at the drop of a hat, about the silliest small things, like a child would do.

Any help or advice would be appreciated