EA accounts keep switching HELP

Hi all. 

I recently bought a sims pack onto my ea account. Apparently I have 2 accounts.

My problem is that I have disconnected the other account from everyhting, but every single time I open sims, it goes onto the wrong account without the new packs.  This account isnt even logged in anywhere.

I am by no means computer smart and im about to roll into a ball and cry - it has been 3 hours of this