Who do I speak to re: possible ASD?

[TheRugbyValkyrie]

My 12 year old son, youngest of four, is odd. He has always been odd.
I use the word odd because I really struggle to work out what his issues are.
He is mildly obsessive has fixations, emotionally immature and distant. He has no empathy - understands intellectually but doesn't feel. Is aggressive but no longer violent. Has absolutely no appetite control and will raid cupboards/fridge/freezer.
I have major battles with him about personal hygiene, clean clothes etc.
I'm not sure who to speak to first.
He is quite intelligent but does the bare minimum to avoid getting into trouble, so I don't know if school is the right place to start.
I thought the GP, but everything is so woolly. In addition, I have MH issues and I'm aware that some of his issues (not mentioned here) overlap with the things that do bother me. I also had a bad experience when I was told by a Parent Support Worker that all his issues were either my imagination or as a direct result of MY illness.
Any advice gratefully received.

[AdelicaArundel]

"I was told by a Parent Support Worker that all his issues were either my imagination or as a direct result of MY illness"

Oh Lordy...that's just not good. I'm sorry you had that experience.

Is your GP generally supportive? If so, I would talk to them first.

[nellieellie]

I would say, either go to GP and ask for a referral to relevant agency that assesses social communication issues, or, ask the school to refer to relevant agency. You could also google NHS children’s services in your area, specifically see if there is a child development team. Then phone them and ask quickest route. You can also get telephone advice and support from the National Autistic Society, and look for local autism support groups for help.