Again this is your choice. Weigh it carefully. As a Wiccan just remember not to wear that pentagram or any other self identifying jewelry or dress etc... Until you move away because once they see you you will be in hella trouble.
In regards to the slander that from that letter and announcement it is only damaging if you want to continue to be around them
in your case if you want a relationship with your family then you might as well stay or fade. Move away so you can be yourself and continue to humor your family over the phone