Slapping myself in the face whenever I get an angry thought

I've fallen into this habit recently. By the time I get to speak to my therapist next, it will have been 9 weeks since we last spoke (a combination of her having had to take time off and me going abroad), so I have basically no outlet to talk about it.

I could scream the house down as a child when I was angry, but that's not exactly an adequate option as a 26 years old.

I have no other coping mechanisms and it does force me to stop thinking about it cos I know what I'll start doing if I do. I would also sometimes tie an elastic band around my wrist and flick it. 

It doesn't help when my dad tells me off for 'misbehaving', which is probably the main trigger right now.

I've never had anger issues but I don't recall things ever being this bad in terms of things building up.