Dealing with unwanted content online is a headache, but you don't have to stay...

https://station-wiki.win/index.php/How_to_Remove_a_Telegram_or_WhatsApp_Screenshot_Posted_Publicly:_A_Practical_Guide

Dealing with unwanted content online is a headache, but you don't have to stay stuck. Start by taking dated screenshots for your records before you do anything else