WordPress says my username/email address doesn't exist. How do I log in?

Hi, I’ve messed something up on my wordpress (unfortunately I’m quite new to .org) and I have no idea how to fix it! Here’s the details;

I recently bought hosting with 1&1 and a domain with namecheap.
Until I could get my domain to point to wordpress, 1&1 was using the domain name “s601003897.websitehome.co.uk”.
The domain name “maybemica.com” is now pointing to wordpress (or it was), but my media files all still said they were at s601003897.websitehome.co.uk SO I changed something in the settings to maybemica.com so that hopefully my media files would point there, and www.ads-software.com kept saying “maybemica.wordpress.com doesn’t exist, would you like to register it?”. The page wouldn’t go away no matter what I clicked on so eventually I just said yes. This created the website but logged me out of www.ads-software.com and into wordpress.com (I have an account over there too for a different website, don’t ask me why they’re separate haha) for some reason.

Anyway, now it’s saying my username/email address doesn’t exist on www.ads-software.com and won’t let me log into it, and my website (maybemica.com) is pretty much broken! I have no idea what’s happened or how to get it back, could someone please help?

Thank you so much, I’m having a heart attack over here!