Is it selfish to want to be there for my friend?

[RaymondDsouza]

My best friend is going through a really tough breakup and she needs me right now. She has been calling me every night crying, and I feel so guilty every time I have to cut the conversation short to do my homework. I have a huge assignment due tomorrow and have thought to myself just write my assignment but I know I am not doing that. I feel like I am failing as a friend and failing my own career at the same time. I got so torn last night. What would you do?