Inbex.php hacked

Hi,

My blog (https://www.sweatlikeapig.com) has been hacked several times over the past few weeks. It has mostly been my htaccess file that has been modified (which was therefore only affecting the way my site was being viewed on mobile devices), which I have been able to edit myself. However, now the inbex.php file has been changed and as a consequence my blog is not loading at all.

Would someone be able to take a look at my inbex file below and tell me what has been modified so I can fix it? My knowledge of HTML is very basic so please be gentle. Thanks! In the past week, the other files that have been modified are: cgi-bin, temp, wp-admin, wp-content and wp-includes. Would I be better off just restoring my site to a back up from a week ago, and then implementing the steps to prevent this from happening again?

[ Moderator note: redacted. ]