how to control/stop laughter during pdps and viva??

mbbs 1 here and i am FED UP of how much i laugh during pdp and with teachers. sometimes i start thinking about random shit and burst out laughing. ive tried biting my cheeks, pinching myself hard, squeezing my fingers but nothing works.

today i laughed in front of seniors because i remembered a joke they made yesterday. PLEASE help. im not concerned about laughing during pdp but viva and internals mei hasi aagyi toh ill be fucked. pls help seniors.