Dental deep cleaning for gingivitis

My dentist said my gums are swollen and red so I need a deep cleaning for gingivitis...I looked up son YouTube videos and now I’m FREAKING OUT. My wisdom teeth are KILLING ME and I have to go do the deep cleaning before they take any of them out...anyone have any advice??? Or if anyone has ever had this done before can you put my mind at ease and give me details?! 😩😭