WordPress Malware Removal Specialist Needed

I tried to install an SSL certificate and website went offline, I talked with a freelancer if I did something wrong, but he said Wordpress website has a malware and that's why it is offline, need somebody who will clean malware but also make sure that the website will be working after that, We had these problem before and we just installed new wordpress version and plugins and website got all screwed up, all pages, pictures, plugins didn't work properly cause website is using lots of plugins and scripts from old worpdress version .
P.S I tried contacting hosting support but they are useless. They not gonna help, it is a self serve hosting