feel like giving up

I love my daughter with all my heart. She is 11 weeks old. But every day I struggle with her. She doesn't nap longer than 30 minutes so she gets overtired. I've tried every thing under the sun to get her to sleep longer but she just simply wont. I absolutely dread the evenings because by 6pm shes an absolute nightmare. My husband works long hours so by the time he gets home my daughter will either be asleep or she'll be so fussy that he cant calm her and I end up having to take her. I miss my old life so much, I feel defeated and absolutely alone. My Dr prescribed be medication for post partum depression but I dont think it's working. I feel so much anxiety.