If you confirm that your bishop effectively or even implicitly endorsed Trump, I suggest you consider withholding all or some part of your offerings to the church, donate that money to the candidate or charity of your choice, and write to your pastor, the bishop and the nuncio saying what you did and why.  How long you continue to withhold that money would depend, I would think, on the response you get.  You may find a way (if you think it appropriate) to support your parish but not the diocese.