Having trouble staying logically consistent during debates.

How exactly do I ground my reasoning for abortion being wrong even in cases of an embryo not being genetically related to the pregnant person? I usually would argue some form of moral obligation to sustain the fetus but then I'm asked why I don't think there's a moral obligation to sustain the life of the violinist?

I've also been told that I can't argue parental responsibility considering that even if they aren't related I still think abortion is wrong, Can someone help me fix my logic?