ASD son wants to be female

[Purpleraiin]

Please don't rip me to shreds if i use incorrect terms, I'm new to gender issues and ND, happy to be corrected though..
I'll try to keep it simple and brief.

Son not long turned 16. Around 2 years ago I found messages discussing his gender confusion with friends, spoke to him and he Confirmed he was confused and felt he was meant to be a girl. He couldn't really elaborate On this, it was just how he felt.

I asked the GP for help so they refered to a psych. The psych stopped the appointment 20 mins in and queried ASD. I confirmed this is something we've considered for a long time but haven't seeked diagnosis. He refused to continue the appointment and said my son needs assessing before anything else can be done about his gender confusion, but he also shouldn't have been refered to psych to begin with as they can't help.
So 8 months ago he got his ASD diagnosis, the generder confusion was mentioned during assessment and I was told its very common in people with ND, he would likely change his mind very soon, and that they'd mention It in the report so the GP could pick back up on this. We've heard nothing since and I really don't know who to contact for help.
My son is still adamant he feels he's a girl, he doesn't speak about it but will occasionally ask if someone can help him yet. He's growing his hair long but that's as far as he's gone in terms of making changes with himself.

Given how long he's now been feeling this way, I'm not convinced its just a passing phase for him. If the psych said he shouldn't have been refered there to begin with for gender confusion, and the GP hasn't helped any further since the ASD assessment, I am totally baffled on who I'm meant to turn to for some help.
Has anyone been through similar who could offer any pointers??

I would take the line that it is fine to be gender non-conforming, but you can’t change sex. The push from a section of society to be affirmative at all costs is, in my opinion, harmful for already vulnerable young people. Online content is a minefield, so I would keep tabs on that. Worth looking at Transgender Trend and posting on the sex and gender board on here, too.

Personally, I suspect much is actually related to ASD difficulties e.g. social difficulties - some think because they struggle to fit in with peers of the same sex there must be something ‘wrong’ and they can’t possibly actually be their sex, when in reality the difficulties stem from the impairment arising from ASD. With that in mind what support is DS receiving regarding his autism?

Thank you for the reply!
I did initially try to go down the route of cant change sex. He's actually spent a good couple of years before I knew about it though researching. He is high functioning, intelligent and intends to go into medicine himself, so has a strong interest in that field and is well aware of what's available to people wanting to change. The only thing he has currently asked to have is something to for hormones.

My worry is that his feelings are due to ASD difficulties as you've suggested. I'm worried to help him take this any further In case that is what's behind these feelings, then he regrets it when he's older.
He isn't actually receiving any support. He's in mainstream school, several years ahead compared to his peers academically, has a good group of mixed gender friends in school, he doesn't feel he needs any support so will not accept any.
The one thing I noticed, I've come across so many messages on his phone from friends declaring they are now non binary, gender fluid etc.....this all started around the time his school started pushing these things into sex education and PHSE lessons. Then less than a year later I find my son telling his friends he thinks he's meant to be a girl.
Adding all that together, I'm really concerned his feelings are largely down to all of that, but obviously I can't be certain and I don't know where to turn to get the help and find out.

As well as speaking to Trqnsgender Trend, I would find out exactly what is being taught at school and speak to Safe School Alliance.

I would not be affirming and would stick with you can’t change sex, because you can’t.

Thank you! I have never heard of either of those, I'll give them a Google and see about contacting both.
Luckily he is in year 11 now so won't be at school much longer. I do honestly believe the things taught in those subjects at school have caused some serious confusion and issues for him though