still getting the 500 Internal Server Error

I got this message while trying to active SEO URL’s.
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at webmaster@mydomain.com to inform them of the time this error occurred, and the actions you performed just before this error.
More information about this error may be available in the server error log.
Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

This is the code that inserted on the .htaccess file and I got it from here…viewtopic.php?f=190&t=173094&hilit=500+ ... r&start=20
______________________________
Options +FollowSymlinks

# Prevent Directoy listing
Options -Indexes

# Prevent Direct Access to files
<FilesMatch "(?i)((\.tpl|\.ini|\.log|(?<!robots)\.txt))">
Require all denied
## For apache 2.2 and older, replace "Require all denied" with these two lines :
# Order deny,allow
# Deny from all
</FilesMatch>

# SEO URL Settings
RewriteEngine On
# If your opencart installation does not run on the main web folder make sure you folder it does run in ie. / becomes /shop/

RewriteBase /
RewriteRule ^sitemap.xml$ index.php?route=extension/feed/google_sitemap [L]
RewriteRule ^googlebase.xml$ index.php?route=extension/feed/google_base [L]
RewriteRule ^system/download/(.*) index.php?route=error/not_found [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !.*\.(ico|gif|jpg|jpeg|png|js|css)
RewriteRule ^([^?]*) index.php?_route_=$1 [L,QSA]

### Additional Settings that may need to be enabled for some servers
### Uncomment the commands by removing the # sign in front of it.
### If you get an "Internal Server Error 500" after enabling any of the following settings, restore the # as this means your host doesn't allow that.

# 1. If your cart only allows you to add one item at a time, it is possible register_globals is on. This may work to disable it:
php_flag register_globals off

# 2. If your cart has magic quotes enabled, This may work to disable it:
# php_flag magic_quotes_gpc Off

# 3. Set max upload file size. Most hosts will limit this and not allow it to be overridden but you can try
php_value upload_max_filesize 999M

# 4. set max post size. uncomment this line if you have a lot of product options or are getting errors where forms are not saving all fields
php_value post_max_size 999M

# 5. set max time script can take. uncomment this line if you have a lot of product options or are getting errors where forms are not saving all fields
php_value max_execution_time 200

# 6. set max time for input to be recieved. Uncomment this line if you have a lot of product options or are getting errors where forms are not saving all fields
# php_value max_input_time 200

# 7. disable open_basedir limitations
# php_admin_value open_basedir none

I have full permissions to the server so if I need to change something, then please let me know.

I am running cPanel 62.0.15 and I know mod_rewrite is activated because I am using it on other websties. Opencart version 1.5.6.4

Thu Mar 02 11:57:00.416685 2017] [core:alert] [pid 22781] [client 68.44.157.7:62815] /home/mydomain/public_html/.htaccess: Invalid command 'php_flag', perhaps misspelled or defined by a module not included in the server configuration, referer: http://mydomain.com/admin/index.php?rou ... 0188b160c6
[Thu Mar 02 11:57:00.416461 2017] [core:alert] [pid 22781] [client 68.44.157.7:62815] /home/mydomain/public_html/.htaccess: Invalid command 'php_flag', perhaps misspelled or defined by a module not included in the server configuration, referer: http://mydomain/admin/index.php?route=s ... 0188b160c6

change:
to

Ok... so here is what I now have.

"The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator at webmaster@modernwarriorconcealment.com to inform them of the time this error occurred, and the actions you performed just before this error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request."

My OC installation is at the root folder and this is where I placed the .htaccess file.

Here is my error log on my server
"[Mon Mar 06 14:22:48.080755 2017] [core:alert] [pid 10869] [client 68.44.157.7:52723] /home/mydomain/public_html/.htaccess: Invalid command 'php_value', perhaps misspelled or defined by a module not included in the server configuration
[Mon Mar 06 14:22:48.080275 2017] [core:alert] [pid 10869] [client 68.44.157.7:52723] /home/mydomain/public_html/.htaccess: Invalid command 'php_value', perhaps misspelled or defined by a module not included in the server configuration"

change to if you futher down, there are some more active, just uncomment them one by one till it works.

remember when using chrome to refesh each time by pressing shift F5 followed by ctrl F5