Wanting a baby and dealing with depression

Hi everyone, I'm 23 years old this month and I've wanted to be a mother ever since I could remember. My depression is up and down but my mind has never changed on wanting a child. I've been my boyfriend for almost three years and I feel like he would make a great loving father. Here's where it gets tricky....depression runs on both sides of my family...unfortunately cancer does too. I am trying my hardest to live a healthy lifestyle although I admit I could eat better and excersize once in a while. My biggest fear is my child having to grow up with depression. I would never wish this on anyone but I've always felt like I was put on this earth to be a mother. I would like some input or advice please, I'm fragile at the moment so please be nice