We do not provide upgrade services on the self hosted platform unfortunately.
At this point, you would need to do the following
Backup backup backup. Make sure you have both your files and database backed up fully
Upload a fresh set of files from your client area (your site will be broken at this point)
Upload the requirement checker from here -
Upload the requirement checker to your server, and run this
Address any items showing in the requirement checker
Run the upgrader from /admin/upgrade