Autistic child struggling to cope after starting school

So I just want some advice for how to help my autistic son. For clarity I should also add that I am autistic too, although my wife isn't.

My son started school in September for the first time and ever since he is really struggling. Every evening he comes home and has meltdowns then crashes and just sits on the sofa zoned out like a zombie. Everything upsets him, even the slightest little thing that is different from his routine or the way he wants things makes him dissolve into tears, crying his eyes out.

I hate seeing him like this and I just want to help him. The thing is, he is so shattered after school that he's not up to doing anything else. So we end up doing nothing as a family, like in the evening and weekends. Now what I'm not sure of is is this good for him? Is this what he needs? Because I don't want him and us to end up doing nothing but equally I don't want to force him to go out and do stuff he's not up to, because as an autistic person myself I know how destressing that feels. 

Any help or advice with this or general coping strategies for him with school would be greatly appreciated