[NSFW] my blog has been hacked

Hi I am new to the forum and have no knowledge of technical stuff of word press blogs.I hired a girl to install the template I bought from her and she has been great, but recently I was hacked. I can’t edit any pages at all it reads a syntax error on every page and some appear to be missing like my 404 page. Even though my blog is visible and appears in tact online, it isn’t. I nned to please help me that I can trust fix this problem I have no idea what to do or how to do it.

This is the error: Parse error: syntax error, unexpected T_STRING in /home/content/m/s/n/msnikkisantana/html/naughtinikki/galleries/core.php on line 366

I emailed the girl who I purchased it from but she has not answered me and its been a week already.
you can email me directly please just look for my blog naughtinikki and go to the about page and scroll down you will see my email address.

Nikki