possibly my sites been hacked.

Hallo

I had some problems with the fonts in the right hand side menu on this site https://www.swimmingwithjellyfish.org/.
i asked on the plugins and hacks forum for help, and got this back from one

Domino_ukraine wrote:
wp-content/themes/master/style.css – row 179:
#sidebar a {
color: #8A0; !!!!!! change this to your color !!!!!
text-decoration: none;
}

Then i logged into my dashboard and all the visual info was gone. It had changed in other words. And the video on my homepage was gone. I thought maybe its stat-counter or the newest WP update but wasn’t sure. But i DIDNT do what Domino_ukraine advised.

Now today i looked again and all my plugins in the right hand menu bar don’t work, the missing video is back, and the fonts on my right hand side menu have been changed to what i asked on the plugin forum, but i didn’t do it.
Were can i get help with this?

lisabiziou