I feel so alone

I'm having a pity party and need some encouraging words. My mom who is my best friend is completely against me having another baby right now. My step dad is right there with her. My doctor doesn't think it's a good idea either. I have bipolar. That will never change. I will always have bipolar and I feel that now that I am in a spot where I am mentally available is the best time to have another baby. Am I just being selfish?