Someone keeps changing my passwords. I've changed passwords billion times a week?

[Paci]

So first it started on my twitter. I tried to log in to my twitter but it said that my password was wrong. So i clicked the forgot password thingy and checked my e-mail (please note that i have 2 yahoo IDs. The one i used for twitter is the first one), and got my twitter back.

The next day, i tried to log into my Email address (1st yahoo ID, the one i used to get my twitter password back) and i couldn't log in. The problem was the password. So i clicked the "i can't access my account" thingy, picked the "send reset password link to your alternative e-mail address" way (my 2nd Yahoo! ID), and got my 1st Yahoo ID back, that was the first time..

The next 2 days, my twitter, my 1st Yahoo ID, my alternative Yahoo ID's passwords were all changed. Same thing as my twitter incident. After an hour of moving around to get them back, i got my twitter and 1st e-mail back (I got my 1st e-mail by using the secret question way, because i couldn't open my alternative email). But after i went offline for about 2 hours, it happened again. I tried ways to get them back and got sick of it. So i backed down and tried to find any solutions for my problem. Many people say it's keylogger. But i don't really know what that is and how to remove it. Or maybe some of you know what this thing is? Other than keylogger? I've changed it million times a week but it still happens. I've tried to contact Yahoo customer care and Twitter customer care, but they haven't replied.

Please, i really need your help.
P.S: I've been trying to download Ad-aware but since my IDM was registered by a fake ID, i can't download anything=.= A little help with this too, maybe?