Lost

Today my richardsheehan@rocketmail.com email account disappeared from my computer.
Rocketmail is a Yahoo account. My address boox and all my addresses also disappeared!

Also lost all evidence of my Foxfire-Mozilla web browser.

Both rocketmail. com and Foxfire were default positions.

What happened?

Why did it happen?

How can I have a safer and simpler web life??

How might I retrieve my address?

How might I retrieve my 'bookmarks,' and "favorits?

How best I retreat to a safer position?'