Error 500 and htaccess Problems

Hi.

Complete WP novice, so apologies for any idiotic questions out the gate.

I’ll try to be brief.

Was updating a few things in WordPress, suddenly got Error 500 when I tried to each the admin side of the website. Looked around the internet and saw a few resolutions. First I tried upping the memory on my own, didn’t work. Tried modifying the htaccess (for the first time) and that didn’t work. Disabled plugins which also didn’t work, along with deleting all extra themes. This happened around a month ago (maybe more), I got a bit frustrated and gave it a break. There are two other things I can think of; being a bit boring and calling the hosts to see if there is anything wrong on their end or reinstalling wordpress. Any help would be appreciated on this one.

Second problem. Upon a glorious return to trying to fix the thing 1 month later, I tried the same code out on the htaccess:
AddType x-mapp-php5 .php
AddHandler x-mapp-php5 .php
And proceeded to seemingly break any entry into my website, It lists some php theme access stuff I don’t understand. I’ve deleted the extra code but the problem remains. Oddly I tried accessing it on my phone and it worked fine. It could be a non-issue and is probably easily fixable. But as I said, I am a novice and don’t know what to do.

http://www.bigfriendlygaming.com

Thanks in foresight,
Kcs