how should i handle this situation with my son?

my sweet son has asd. I write about it sometimes. He started school (not actual school aba therapy) recently and is being extremely clingy. I feel like he may have some separation anxiety.

I entertain it for a while but it gets very exhausting. He's been climbing and jumping on me and wanting to be held all day. He is currently on my back as if he is trying to get a piggy back ride lol he has not stopped touching me or wanting to be held or grabbing me since I woke up this morning.

what am I supposed to do? boundaries is very important in my household. But I don't want to offend him or cause further anxiety for him. He's driving me nuts and I kinda just lost my cool and yelled because he keeps jumping on me and ripping my fvcking hair out and I don't like to yell or raise my voice at them (my kids)