For future reference, it's an extremely bad idea to use the same password for multiple places. I'd be willing to bet a small amount of money that you use the same password for a banking site, or some site that holds more personal and/or important information than here and your email. Bad, bad idea.
If you have trouble remembering passwords, there are utilities and programs out there that specifically address that problem, like 1Password:
http://agilewebsolutions.com/products/1Password
Also, "hacked" entails that someone used some method of bypassing your password to illegally gain access to your accounts -- which doesn't sound like the case here. It sounds like someone simply guessed your password (was it a strong password, or something easy like a word, phrase, pet's name or birthday?), then tried the same password at another site. This is
NOT hacking -- it's simply the result of choosing an easy-to-guess password. Think of it as leaving your front door to your house wide-open, then someone comes while you're away and steals all your stuff... you'd have a hard time convincing anyone that they "broke in" to your house, since they didn't "break in" at all -- rather, they waltzed right through the gaping hole you left open for them.
This may or may not be the situation here; I'm just putting out a fair warning that people need to choose stronger passwords going forward, and no password should
ever be used more than once. Wanting to remember easy passwords and avoid forgetting them, or using the same password more than once so you only have to remember a single password is no excuse -- I'd like to just leave my car wide open so I don't have to go through the hassle of putting the key in the lock (it would be much easier!), but that would just be plain stupid and I stand more to lose than I do to gain.
Just information to think about in the future.