Anyone had success with anti-anxiety medication?

My son is 17 and has not been prescribed anything for his autisic symptoms other than dietary supplements.

We love him to bits. He is profoundly autistic, non-verbal with profound learning difficulties and very much in a world of his own.

He has bouts of anxiety, not every day but frequent enough for it to become a challenge outside the home. OCD has gone from 'quirky' to making our lives very limited.  He has now started with teenage tantrums that are happening more and more when we are out and about (shop is closed, things in a store have moved, train is late, bus takes a wrong route etc). As well as tantrums he will also refuse to move and can literally stay in the same spot for hours.  We are struggling to get him to school too as he refuses to come out of his room in a morning - his school is the best school for autism in the area and we all have a great relationship with the staff and they are fantastic with him.

Now - I think he would benefit from some mild medication to help him stay calm with life's disappointments my husband thinks differently.  I know literally nothing about anti-anxiety drugs so please feel free to give your opinion.

Can anyone share experiences or offer advice?

Thank you