Arm rest recommendations for sitting in bed

I am in bed all day everyday and get shoulder pain from not having arm rests, I use a pillow sometimes but it’s too bulky. I have my arms up a lot because I play video games.
Has anyone got any recommendations for a non bulky pillow or alternative arm rests that can be used in bed?
I sit against normal sized pillows and have a small double bed. I struggle with sitting posture and being comfortable because I am very sensory sensitive.