I think that's just normal, tbh, and probably true of most relationships.
Gently OP, while it's true that how our partners speak to us can affect our mood in the moment, it usually passes and is resolved.
However if we are feeling suicidal then someone affecting our mood negatively could have serious consequences, like you feeling so low you said on here that perhaps your baby is better off without you etc.
So for you, really focusing on and building up your self worth and confidence outside of the relationship is vital so that if you two have a row it doesn't sink you into suicidal ideation.
Hope that made sense, not sure I explained it perfectly.
It's very, very worrying to hear someone say they think their child is better without them and be suffering with suicidal ideation / suicidal thoughts, so people have latched on to that bit of your post as they are concerned about you and it's perhaps more shocking a statement than you realise because you're living with it.
I've been there and remember telling a friend how I felt and she burst into tears panicking about me whereas I was almost numb to the idea of those thoughts.
People are trying to help you 