Banned and lost

I want to start a family, but everybody says I'm to young to throw my life away. I honestly don't think an early marriage and having children ruins your life. My mother married at 17 and had her first baby at 17 as well. I don't want to follow in her foot steps but I want to start a family. The problem Is she hates my boyfriend, whom I've been with for some time now and iam completely banned from him. It feels like a Romeo and Juliet thing. 
​She tells me to be happy and do what makes me happy, he makes me happy so what do I do?