Is this wrong?

I have a genetic Mental health illness and it has been passed by many including me. I have decided that I do not want to have a child for this reason and a few others such as if I get pregnant I will have to quit my medicine, my mental health will deteriorate, the medication will be in my body and I will not be able to breast feed. I have been very certain with my decision but my family thinks that I am being selfish for not wanting children. I am feeling terrible about it now and don’t know what to think anymore. Can I have some advice please?