I'm pregnant by my husband's cousin
I am not sure what to say to you about that.
I'll consider trying not to see him again. I've already hidden my feelings for a while.
I hope that was a one time only mistake.  I hope you find a way to resolve this amicably. Your partner's family is something you need to try and not get that involved with but am sure you already know that.
They already know about the situation. I will now not see him anymore.
It is good that you arrived at this conclusion. If you are married, you are expected to stay faithful to your significant other.