Sorry to say Grant that this is a familiar story as exactly the same happened to me over Christmas. Ironically it was Pokerstars who alerted me to a potential hacking problem. It does happen to the best of us even Daniel Negranu!
It took me a week in total to get a resolution.
I did wrestle control back of my hotmail account by recovering the account via security questions and deleting the said hacking alternative email id, changing security questions and making it a hard password.
My advice is to :
1) Try to borrow or use another device to reset your hotmail (I did it via an IPHONE). This is in case you have VIRUS or keylogger trojan etc.
2) Inform support@pokerstars.com that you have been hacked and to make sure that the account is frozen until this gets resolved.
3) Open up a GMAIL account as this is a lot more secure with two phase login process
4) Make the request to pokerstars to change your email ID
5) Ask for a PIN code that forms a two stage commit to access the Pokerstars site.
6) Come up with a password scheme so that you have different passwords for each application you have. Its a pain but the only way IMO.
Hope this helps, when the dust settled for me I put my issue down to a rogue Facebook page/app that asked me for confirmation/relogin with my password and it snowballed from there, given I work in IT I should have known better!