Site not loading including wp-admin

Hi, running multisite and multi-network,
was editing theme files and tried to save, but server timed out, then nothing would load at all. Stays on the page but just a blank screen. Wasn’t editing C-Panel or domain mapping or anything major.
Other sites in the multi-network are still working including WP-admin
No idea what I could have done or if its a hosting issue? Strange that it hasn’t affected other networks (which are all parked domains pointing to same server as main blog is on: ie they are all subfolders in the main blogs directory, so thought they’d be down if it was a cPanel level problem.)
Would appreciate anyone’s input as I can’t see where to even start with this as cannot access dashboard and don’t want to mess with cPanel while I can’t see the impact of changes I make.
Thanks

Dallas