newly diagnosed with autism

Good Evening all,

my 26 year old son has recently been diagnosed as autistic,,he can''t cook,he can't clean,aswell as many other things he needs help with.he relies on me,or his grandma .the medical professionals have told him he can apply for P.I.P..  but  iv'e heard P.I.P isn't easy to claim for autism.
Can anyone give me some advice about P.I.P 

Thank You