It looks like your site was defaced, most probably weak password or some backdoor in CMS you were using. Your original files were replaced, so if you have a backup of your website, we can restore it, otherwise I am afraid it must be re-created from scratch and I cannot help you much about it. Regarding the future protection, if there are logs on the server made by your hosting provider, we can trace down how the hack was performed and perform some actions (improve the password, scan for malware all the computers that were used to upload the content) but I am afraid that the current budget would not be sufficient for that.