Our empathetic nature is my destruction

I (July Cancer, F) dated Capricorn men, a December (cheated) and January (ghosted but trying to return but I rejected).

These two relationships did not last for a year, even at the course of it I was too kind, understanding, empathetic with them that I forgot to see their red flags.

I wanted to be unkind, to protect myself and go back inside of my shell, but I cannot seem to do it. That is not who I am. I do not want to hurt people but all I get in return is this.

I was so understanding that I lost myself to see that they were taking advantage of me. My genuine feelings towards them did not reciprocate.

I am tired of this, I am tired of being hurt. How do I keep being kind if this is always the result.