Can't log in to Admin, no error

[ThudGames]

Hello,

I recently updated to 1.7.6.7 and I have had nothing but issues with the back office/admin log in. I currently cannot log in, I put in the information, the page refreshes instead of logging in. I have cleared my browser cache/cookies/etc, I have turned off my ad blocker, I have deleted unused files in the PHP, I have changed my PHP version (although I can't remember how I did that now or how to check). I am NOT proficient with this, I usually just Google things and try and work out what people mean by the suggested solutions, but I haven't been able to find anything, any information. Please help.