Urgent! I have messed up big time!

Hi all,

I am new to WordPress and have been editing quite successfully a website that was built for me. The thing is I changed the premium theme from Twenty-Eleven to a newer style (Bizstudio), and then accidentally deleted the old premium theme. To make matters worse, I was trying to update the look and feel of the initial page and ended up in the permalinks area. Just as a test I rewrote the permalinks using the same details just to see if how the change could be made and ever since then my webpage will not load. Instead I keep getting an error (404) and I have no clue how to fix this. I am afraid that I have done some irreversible damage and desperately need some help. Can someone please advise me in easy to follow steps what I need to do in order to rectify this matter asap. I have included the url, which is https://www.daddyshouse.ca/ – the first page I was trying to update and the the url to the other pages https://daddyshouse.ca/blog/ which has also lost its theme. Lastly if you delete a premium wordpress theme do you have to pay for the same thing again? Please help me I am feeling really silly right now ??