bad mom

I feel like such a failure already. I'm a single mother living at home with my mom, I'm 20 and I'm barley a freshman in college.. all my daughter does is cry anymore it seems like, even if I'm holding her. I try gripe water, I try feeding her, I try the paci, nothing works. I'm exhausted and I cry probably as often as she does. my head hurts, I have no help. I'm exclusively pumping and I only get to do that every 4-5 hours because she's screaming so much, so I'm worried I'm not producing as much as i should be.. I over feed because it's the only time she isn't screaming. i dont know what the hell to do anymore. we're both crying as I type this. I can't freaking hold her anymore for hours letting her scream in my ear, I'm just so freaking exhausted. I need  encouragement or something, i dont know how women do this on their own