Fatal Error and/or blank screen

Hello, so I’ve had an issue that has been ongoing for some time and I have talked to my host provider, BlueHost. several times now with no answer. I have recently  had installed 500k profiles along with pics etc however the process was stopped as the installer said there is an issue on the host end. However as mentioned they have not been able to provide me with a solution or answer.

My hopes is that perhaps maybe SweetDate may have some insight to my issue, anything that gives me a lead to look for a solution or perhaps even the answer here.

Some times on the Home Page I get a fatal error. Some times the site “kicks in” and I can surf it a bit, but everyday on first log in it crashes with the Error or it is a blank page.

Last answer from BlueHost was that it was a plugin that is creating the issue, so aside form BuddyPress, bbpress, rtmedia, and wordpress installer. I don’t get that immediate crash on initial visit however I still get it in my Error Log and when I search members, putting in I am a… looking for a…etc, it will crash to a blank page.

Here is the recent Log: (it is always the same)

Normal
0

false
false
false

EN-CA
X-NONE
X-NONE

MicrosoftInternetExplorer4

[18-May-2017 20:40:11 UTC] PHP Warning:  mysqli_query(): (HY000/3): Error writing file ‘/ramdisk/mysql/tmp/MYExDDfT’ (Errcode: 28 – No space left on device) in /home3/sexualaf/public_html/wp-includes/wp-db.php on line 1877

[18-May-2017 20:40:11 UTC] WordPress database error Error writing file ‘/ramdisk/mysql/tmp/MYExDDfT’ (Errcode: 28 – No space left on device) for query SELECT u.ID as id FROM 117_users u WHERE 1=1 AND u.ID IN ( SELECT ID FROM 117_users WHERE user_status = 0 ) ORDER BY u.display_name ASC  made by require(‘wp-blog-header.php’), require_once(‘wp-includes/template-loader.php’), include(‘/themes/sweetdate/single.php’), get_header, locate_template, load_template, require_once(‘/themes/sweetdate-child/header.php’), wp_head, do_action(‘wp_head’), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, wp_enqueue_scripts, do_action(‘wp_enqueue_scripts’), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, bp_enqueue_scripts, do_action(‘bp_enqueue_scripts’), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, bp_activity_mentions_script, do_action(‘bp_activity_mentions_prime_results’), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, bp_friends_prime_mentions_results, BP_User_Query->__construct, BP_User_Query->do_user_ids_query

 [18-May-2017 23:32:31 UTC] PHP Fatal error:  Allowed memory size of 268435456 bytes exhausted (tried to allocate 32 bytes) in /home3/sexualaf/public_html/wp-includes/wp-db.php on line 1841

[19-May-2017 00:14:07 UTC] PHP Fatal error:  Allowed memory size of 268435456 bytes exhausted (tried to allocate 72 bytes) in /home3/sexualaf/public_html/wp-includes/wp-db.php on line 1841

[19-May-2017 01:25:50 UTC] PHP Fatal error:  Allowed memory size of 268435456 bytes exhausted (tried to allocate 32 bytes) in /home3/sexualaf/public_html/wp-includes/wp-db.php on line 1841

The Bottom 3 are repeats and is what usually shows on screen with the initial home page visit. I have a second site, same theme etc.,  I am weary that it is going to be the same.

Also another note is with the members added the site and dashboard has been tremendously slow and I’m curious if there are suggestions to this?

I’m appreciative of any help/suggestions.