Posts have widened and formatting gone

I used to manage my blog almost on a daily basis, but with uni exams coming up I abandoned it and didnt touch it for several months.

I’ve come back to it to kickstart it back into life and the whole blog ahs changed.

The themes dont work correctly as posts are too wide and the sidebar is not on the side! I have no idea what has happened.

My blog is waeshael.wordpress.com

Please help.

Best regards,

Waeshael