Voting Question: My AIM screen name got hacked!?!?

So theres this spam thing thats going on. And i clicked a link from a friend who already had been hacked thinking it was her. Then i had to enter my sn and password to see the window that goes toward the link. now my screen name i.m’s everyone on my buddylist trying to hack them too. & when im on my other SN I see the hacked SN is signed when im not signed in. I tried to reset my password but in order to do that i needed to put my alternative email address when i first registered. the thing is i made it so long ago i dont know what the alternate email was. is there anyway i can delete my screenname or stop this hacking.