Lyric discussion by MuffinMonsterRawr 

Cover art for Obsessions lyrics by Marina and the Diamonds

I got the impression it could be about someone dealing with social anxiety, along with OCD.

"Look, look, just choose something quick People are staring, time to go quick Skin is on fire; just choose something, something, something Pressure overwhelming Next minute I am turning out of the door, facing one week without food"

She can't decide on something as simple as which crackers to pick because of OCD. And she feels like everyone is staring because of her cracker dilemma, so she feels embarrassed and overwhelmed. But at the same time she can't pick crackers because she's overwhelmed by the thought of people staring. She'd rather leave and go without food than deal with the embarrassment of being seen and judged by others. It's something I used to deal with until I overcame it, so that's just how I interpret it.

My Interpretation

Yeah, I would agree with this ^