Four short lines, and almost nothing is spelled out beyond the basics: someone has been hurt by another person, and they can't shake it. The speaker doesn't describe the betrayal or say who "you" is. We only get the aftermath, and that's what makes it feel so raw.
What stands out is how the pain shows up in the body. Not eating and not sleeping are the most basic things a person does, and the speaker can't manage either. The repeated "I can't" at the start of the lines works like a stutter, as if the speaker is stuck and running out of energy. Then the last two lines name the cause: it only takes thinking about the hurt to knock everything off balance.
The mood is quiet, weary, and a little helpless. There's no shouting or blame, just plain admission. The simple wording makes it feel honest, like something said late at night to no one in particular.