#non-native speaker issues

knowing that this person will be the first to lay eyes on this thing you have created and that you love so much. And you're not quite sure if everything you wanted to say was actually explained properly and if it makes sense or if the story flows enough or...

Thank you for your help.  I have a good grasp of the English language when I write, but for some reason this is an issue that keeps bugging me.

if there are any native English speakers out there and reading this. Can you help me out? Thank you.

I'm having issues with the use of comma and full stop before and after quotations.

For example (these are just example sentences that have nothing to do with my fic):

First problem:

IS IT:

"I don't know what to tell you, because I'm not sure what you want to hear." Dean says.

OR IS IT:

"I don't know what to tell you, because I'm not sure what you want to hear," Dean says.

I always use the first option, but there are authors out there who use option two. Is there a definite grammatical rule about this? Because I've been looking in books and on the internet and no one seems to be certain about a definite rule.

Second problem:

IS IT 1:

"I don't know what to tell you." Dean says. "Because I'm not sure what you want to hear."

OR IS IT 2:

"I don't know what to tell you." Dean says, "because I'm not sure what you want to hear."

OR IS IT PERHAPS 3:

"I don't know what to tell you," Dean says. "Because I'm not sure what you want to hear."

OR OPTION 4:

"I don't know what to tell you," Dean says, "because I'm not sure what you want to hear."

I mostly use option one, unless it's very clear that the second part is a continuation of the first part and then I sometimes use the fourth option. But really, number one is my go-to rule. Am I right here? Or am I making a great big mistake.