Grubs in tomatoes, advice?

Hi all, first year gardener here. I have a lovely tomato plant with several tomatoes growing on it but noticed the first one had seemed to slow down and the others passed it up in size. Today I noticed a fat grub hanging halfway out of it, so I pulled the bug out and threw it away.

So my main questions are: 1) do I pick and discard the tomato in question? It seems like it would rot or get more bugs since there is a big hole in it, and I don't really want to eat a grub's leftovers. Also 2) What do y'all like to do to prevent this? I read a little bit about things I can do but am interested if anyone has any tips. Thanks!