What should you do if you attend a Mass where the Priest is preaching something that is contrary to our Churches teachings? and what do you do if there is some kind of liturgical abuse during the Mass?

St. Francis de Sales said that he would receive the Eucharist from a priest if the priest had harlots on the altar with him. Every situation is different, but keep that in mind.

That being said find a place of worship that would not be an occasion of sin, and let the proper people know why you and your stewardship are going elsewhere.