App Slowness after launching. how to fix it.. ?

Please read the details carefully, and before you bid, write a description what you think is the issue so I contact you. (submit only if you have the certainly to solve it ) I have app that shows some videos on the two screens in the app ( home, videos ) number of loaded videos about 10 videos, users can play the video by streaming from our server. App speed was normal, until we launch the app, and it has become extremely slow (ios, androrid) although the app speed was just fine. We found the the API url calling the php server side is taking very long time (so it's not app issue, I can provide you with the API url) and also i found out the not only the screens that has videos are taking time, but also the other simple screen. I contacted the host and the said nothing wrong in the host side, and you can see the performance of the server in the attachment. Some one suggested to modify the queires optimization, however, it was working fine the same queries before with no issue, we got only 500 new users. this is some code of the configuration of the server side php: function recentvideolist () { $db = JFactory::getDBO(); $config = JFactory::getConfig(); $offset = $config->get('offset'); date_default_timezone_set($offset); $currentdate=date('Y-m-d H:i:s'); $tournament_id=JRequest::getVar('tournament_id'); $is_home=JRequest::getVar('is_home'); $user_id=JRequest::getVar('user_id'); $checkpri = "SELECT akeebasubs_subscription_id FROM #__akeebasubs_subscriptions WHERE enabled=1 AND akeebasubs_level_id=1 AND user_id=".$user_id; $db->setQuery($checkpri); $result_checkpri = $db->loadresult(); if($result_checkpri) { if($is_home=='1') { $db = JFactory::getDBO(); $sql = 'SELECT * FROM #__snap_G_video WHERE published=1 GROUP BY id ORDER BY created desc LIMIT 0,10'; $db->setQuery($sql); $datas = $db->LoadObjectList(); $tourment_desc=""; } else { $db = JFactory::getDBO(); $sql = 'SELECT * FROM #__snap_G_video WHERE published=1 GROUP BY id ORDER BY created desc LIMIT 0,30'; $db->setQuery($sql); $datas = $db->LoadObjectList(); $tourment_desc=""; } /* $db = JFactory::getDBO(); $sql = 'SELECT * FROM #__snap_G_video WHERE published=1 GROUP BY id ORDER BY created desc LIMIT 0,30'; $db->setQuery($sql); $datas = $db->LoadObjectList(); $tourment_desc=""; */ }else { $NewDate = date('Y-m-d H:i:s', strtotime("-3 days")); $db = JFactory::getDBO(); if($is_home=='1') { $sql = 'SELECT * FROM #__snap_G_video WHERE published=1 AND (created <= "'.$NewDate.'") GROUP BY id ORDER BY created desc LIMIT 0,10'; }else { $sql = 'SELECT * FROM #__snap_G_video WHERE published=1 AND (created <= "'.$NewDate.'") GROUP BY id ORDER BY created desc LIMIT 0,30'; } $db->setQuery($sql); $datas = $db->LoadObjectList(); $tourment_desc=""; }