Honestly, all you seem to be able to do is throw around the term "bigot" how you claim they throw the term atheist at you. The fact that they still try and convert you after all this time, I imagine, means that they care about you; seeing as how non believers aren't typically handed a get into heaven free card and all. So fuck them for trying to save you from eternal damnation.
That's not to say there way of going about it sounds like a good idea, trying to force beliefs on anyone is a shitty thing to do. But there helping you in the only way an ultra-conservative knows how and there never going to accept that you are an atheist. The fact that you are probably eats away at your parents, prompting questions such as: "where did we go wrong", or "what could we have done differently". So they may now be trying to make up for mistakes they made in the past, to help you going forward in life.
All in all though, they sound like shitty people, you sound like a shitty person who's just as unrelenting as they are in their beliefs.
TLDR; You and your family seem like unpleasant people to be around
/rant