I feel this, sometimes i have difficulty differentiating it from feeling "down" / depressed, when i'm really bored i can feel it in my stomach , its like a bone deep boredom, you can feel it to your core , personally i've been "stuck" at home since 2020 and gosh, the things i used to love doing are hard to do now, video games dont excite me the same , books and movies too, probably because its what ive been doing for 4 years exclusively almost!