merging different accounts

Hi.

I set up an account a long time ago under timuckun@gmail.com (user digialdiague). When I log into that account it asks me to log into a different account and I usually log into my work account (tim.uckun@digitaldialogue.com.au).

I wanted to use my personal account for personal things so I created a third account tim@uckun.com but now I realize that was probably a mistake because it won't accept my public key (I already uploaded it for the other account).

I would like to merge my tim@uckun.com account with my timuckun@gmail.com account and keep my work account separate. I would also like to be able to use the same SSH key for all the accounts.

How do I do that?