Been there! My husband’s a convert and all his family and lots of mine are Protestant, and the subject of faith is a sore one.I’ve even had my grandmother ask me if I believed all this “catholic indoctrination” (her words).The best thing to do is more of what you’ve been doing, respond calmly and with logic to their arguments. Come prepared for all the usual protestant arguments against the faith (Mary, the sacraments, the Pope, etc). It also might help to realize they’re not really thinking their faith through with reason, it’s all based on their emotions: in a sense, it almost doesn’t matter that you have a response to all their arguments against Catholicism, they will still “feel” it’s wrong.