Feeling overwhelmed

Sometimes I feel like I'm doing a good job, but some days (like today) I just feel sooooo overwhelmed. My LO (9 weeks old) normally sleeps pretty well through the night (3-4 hour blocks), but last night she did not. I'm exhausted, she's miserable and has been inconsolable to the point her voice is horse. She has had really fussy periods for about 2 weeks now and it is really wearing on me. My heart breaks for her because she is obviously in distress. I feel like a shitty mom because I can't help her. I get irritated and frustrated with her because she is crying nonstop, sometimes for hours, and then I feel terrible because she is just a baby and can't help it. Sometimes I just look at her and cry because I am so overwhelmed and don't know how to help her. I don't think it's colic, she is not gassy and has normal/regular diapers... I feel like I need a break, which also makes me feel guilty. And even on the good days, I'm questioning whether or not I am doing enough... I don't get the chance to read to her every day, we don't do enough tummy time, am I talking to her enough? Engaging enough? What makes me feel worse is I really, really wanted a baby... after several losses we went through fertility treatments to have her, so why do I feel like this? Thanks for listening to me vent