Strawberry,
You need to forget about/get over the password issue. What's done is done. In fact, the password is a minor issue in the grand scheme of your problem.
Look, nobody can talk to your fiance for you except you. Why are you marrying the guy if you can't even talk to him? Is it shyness? What is it? You were BRAVE **enough to warn him to stop flirting with the girls............and **NOW **you're saying that you're too afraid** to ask him about some weird emails he sent. Honey, that doesn't make sense. In fact, your behavior is contradictory.
How is your mom acting now? Has she calmed down? How about your dad? Is it easier for you to talk to him? Do you think he will understand the situation better? Do you have an older brother or sister that you can talk to? Can those emails be shown to your dad/brother/sister so that they get some idea about how serious this issue is?
You've only been engaged for 6 months. 6 months is just a small chunk from your life. Imagine being married for the rest of your life **to some guy that you don't even trust! 6 months is **NOTHING compared to that. You still have the chance to talk to your parents and show them the email and cancel this rishta if you are that disturbed by it.
You have to take strong action. Sometimes parents, for fear of reputation, can place pressure on kids to do things that turn out disastrous. That's why you NEED to take action. Acting afraid **and **complaining about things like the password and how he should have known better........is NOT going to solve anything. You have to take action.
Tell me........how is your mom taking all of this now? And tell me about your dad. Is there anyone (brother/sister) you can talk to that will support you?
Although I think it's important to talk to your fiance, I'm afraid that (if he's not sincere) he might sweet talk you into giving him** ANOTHER **chance for the sake of obtaining a green card. And for this very reason.....your parents need to be more supportive of you.