Medication.

Nothing that eases traits, which are part of what you are.

There are certain symptoms such as anxiety, and sometimes co-occurring health issues such as depression or OCD which may be eased with medication, but as others have said only a doctor can advise on or prescribe these.

If you wish to try something more natural, ask your local pharmacist for advice.

nothing legal in the UK. ... The Netherlands has options. 

I'm also avoiding discussion of any potential medications, per the community rules.

Ahead of speaking with your GP about ongoing management of your ASD, you might find these resources interesting and/or helpful:

NAS - Formal support following an autism diagnosis

NHS - Treatments that are not recommended for autism

NAS - Warning: So-called cures and dodgy interventions

NICE - Autism spectrum disorder in adults: diagnosis and management

Hi, there may be various medicaments that help managing symptoms but we shouldn’t give advice about that. Here is the rule:

Users should not provide medical or legal advice to other users. Giving medical or legal advice can have serious consequences, even if you’re trying to help another member. Please suggest they get advice from a professional. 

you may need to contact your doctor to get help and prescription for meds 

Not really, no. Some people claim to have found benefit from some probiotics, or B6/magnesium.

For sleep problems, melatonin. For anxiety, anxiolytics (herbal or drugs).

There is some limited evidence of giving oxytocin to children, or for social issues sulforaphane (found in broccoli sprouts and brassicas)  - https://www.pnas.org/doi/10.1073/pnas.1416940111

I don't know of any treatment with really good evidence behind it.