It is defiantly nothing to do with your absence, since I haven't been online in-game for about 6 months and when I returned, everything was were it should be. However, did you meddle with the user panel? For sure, if you do then you get sent to a list of your 'characters' and so you can either reset their home or delete them.
It is best if you change your password right away to avoid anyone breaking in again.
*Edit*
You might wanna make sure you haven't reset your account hun also.