Sperm donor

I'm 23 years old and want to get pregnant. I've always wanted to be a young mom and had plans of getting pregnant by the time I was 25. My mom was recently diagnosed with cancer and only has 2 years to live. I really want her to meet her grandchild and my baby to meet their grandma. I feel crazy saying this but I want a sperm donor. I figure it's better than getting pregnant by someone I barely know. What do you all think?