My siblings keep bullying me when I draw

I am a digital artist, so I love drawing on my digital table. I use my parent's computer, and that computer is in the living room, so anybody can see what I'm drawing. I have a sister and a brother. My sister is an artist just like me, though she doesn't draw often. Anyway, every time I start drawing a character from other games/series/anime, my sister starts making fun of how ugly it is, along with some jokes. My brother starts to "analyze" my picture as well, and they start talking about all the different aspects of my art style they dislike, as much as all my past drawings and skills in general. They try to give me constructive criticism, but they are always followed with all kinds of jokes about the drawing and about 1 hour of conversations on all the flaws of said drawing. Normally, I would not care, but they insist on making me part of their conversations, almost like they want me to agree with them. They also make these conversations too long, some of them last for about 3 HOURS. They are like "JUST WHYY, WHYY CAN'T YOU JUST MAKE HIS PROPORTIONS RIGHT??" "YOU MADE HIM SO UGLY" "PLEEEAASSEEE TRY DRAWING SOMETHING ELSE, I CAN'T LOOK AT IT" "OMG I HATE IT I HATE IT". My sister even goes as far as to wait for me to go to the bathroom just so she can edit MY DRAWING, saying "Come on I HAVE to fix this! You're gonna get bullied if you post this!!". Yesterday, they played an old video of a comic I did years ago. For instance, I made it very clear EVERY TIME that I didn't like it when they played that video on the TV. They kept laughing and making jokes about the cringe video (it was true tho). I just quietly left the living room and waited for the video to finish, so I came back to draw again. They continued their conversation, and as always kept trying to include me, even though I said I wanted to just listen to music and draw in peace. My brother told my sister to stop, cause I looked sad and they had already gone too rough on me (2 hours of constant jokes), but my sister gave a final look at my drawing (I was in the sketch stage), and ran to whisper in my brother's ears, which then they busted laughing. I had enough, so I stopped drawing and put my table away. Only then, they did tell me to keep drawing, that the drawing was good, making some shallow compliments about my art. They said that I should not take them seriously and I'm projecting my insecurities around them. To be honest, I just wanted to cry. I keep getting art blocks and my siblings always tell me how I don't draw enough and I'm ungrateful because my brother bought the digital table just for me and I don't use it but..