Swelling

This song doesn't just talk about a dying love but might talk about suicide as an alternative of heart breaking or in any case an assisted death/suicide by the ones who let you down and didnt love you...

I guess this song is about how you feel after a break up and the only person who can do something about the pain, is the person that caused it. So people start to search for other things to relief the pain, in this case, she uses drugs.
she’s also thinking about suicide, the person who has caused the pain could change her mind, but she wants that person to be clear, ‘cause otherwise the suicidal thoughts will win.

‘hello, how do you feel? what does that mean? what does that mean?’

she wants to know how the other person feels about the break up and she’s a bit confused.

‘hi, I guess I feel high cold sweat, dripping down my body’

this is about the drugs and the effect it has on a human being.

‘are you’re trying to tell me something with your eyes? all I wanna do now is lay down and die if you’re gonna do it you better do it right or my heart wont stop swelling’

I guess her love is playing with her feelings and she wants him/her to be clear. Otherwise she would rather die. He/she is the only one who can save her with his/her love.

Sorry had to modify and add again comment. This song doesn't just talk about a dying love but might talk about an iimaginary suicide as an alternative of heart breaking or in any case a imaginary assisted death/suicide by the ones who let you down and didnt love you...