My heart is breaking into pieces right in front of me

In the past 20 hours, I've only slept for four hours and had one meal. Everyone thinks I'm strong, that I'll get through this. It's either that they don't know me or that they're putting way too much faith in me. I'm weak. I'm simple. All I cared for was one thing. All I worked hard for is now...nothing. I'm so sad. In the past 20 hours, I don't even know how many times I've said "I'm sad" or "This really sucks." Exaggerate I am not. I feel so unwanted and thrown to the side. I feel worthless and hated. I always thought that being cheated on would leave a scar: "What's wrong with me? Why wasn't I worthy of loyalty and love?" And it turns out that one does not need to be cheated on to think those things. I feel the same way now. Why wasn't I worth your love, I gave you my all and all I get is you telling me that you don't love me half as much and that our relationship is dying. It's like you took a knife and stabbed it at my heart over and over again. I feel so hurt. I feel so sad. I feel like trash.