did having autism cause me to give myself a slight lisp and a different accent?

for context, i’m a young woman with autism and diagnosed when i was 12. my family all have very ‘cockney’ accents and speak informally, whereas i have been told my almost every new person i meet that im very articulate, and have been made fun of for being ‘posh’ when in reality i am very working class. i make sure my mouth moves correctly when im speaking, and am very aware of my tongue and lip placement. its completely different from everyone im around, as i have no friends or family who speak like me. i also speak with a sort of lisp? it’s not uncontrollable, and i can speak without if i think about it. however, when i speak, my tongue feels the need to be pushed towards my teeth, but im aware im doing it, and i also tighten my lips so i can feel my tongue between my teeth. for example, ill say ‘super’ as ‘ssthuper’ so its not a full ‘th’ sound but its a mix of ‘s’ and ‘th’ which is why i wont call it a lisp. i’ve always looked for answers online but haven’t found any. i haven’t been able to ask a doctor/therapist as i haven’t been in a long time. is this common with other autistic people or is this just possibly a speech impediment that isnt caused by me? because i feel like i’ve chosen to speak like this, and now i can’t go back. i didn’t speak like this until i was around 9.