changed URL and lost website

Hello guys,

so i was in the general settings of my sliding doors theme, and where it said website URL, i changed it, just under the curiousness of if i could change it. As you can tell i am new to anything like this, and so i have NO access to my website now because my login details to the website dont match my actual website because the URL has changed. really hope this makes sense.

can someone please help on how i can reverse this and gain access again. all comments are much appreciated! ??

Thanks
steve