heartbroken

Been with my partner 4 years and broken up for several reasons. I'm just struggling so bad it's for the best but I'm finding it really hard. I havnt eaten or drank for days I  have sat in my room in the dark for days. I can't seem to snap out of this. I went to see him tonight and he was on his way out somewhere. He doesn't care and it kills me. It's so hard when you love someone so much and the feeling not mutual. You can't make someone love you as much as you try 😔 I feel like I don't even want to be here anymore I'm so low. How am I going to get through this heartache