Can I sue my husbands mistress for messing with him and knwoing that he is married and lives with me. And she is lying about it and gave him a std I got it from him.

No, but you can divorce your husband.

No you can not sue her,

And why do you not seem to be blaming husband ?

You divorce husband and sue him for money

Negligent or perhaps intentional transmission of a STD? Theoretically, but I seriously doubt you are going to find any lawyer who will take the case on a contingent fee.