Imagenie, big hugs for you!
You're not alone. I've been struggling with this thing since childhood too. Sometimes I wish I could turn on the light switch in my brain. Do you have any hobbies? Is there something you can distract yourself with when you feel you're about to sink? I try music, movies, writing, reading, watching makeup tips on youtube

, walking outside, calling my sister or a friend. Anything worked for you in the past that you can try today? I know this whole experience is frustrating, but hang in there!

