TwitterAPIExchange suddenly stops working - php

Question

So I'm making a Twitter fetch website where all the tweets from a specific hashtag will be fetched in real-time with ajax. It all works fine, I thought, until it all suddenly stops working. If I then wait for 3 minutes or so, it then starts working again. PHP is giving me errors such as
Notice: Trying to get property of non-object...
The code I'm running:
require_once '../lib/TwitterAPIExchange.php';
$settings = array(
'oauth_access_token' => "...",
'oauth_access_token_secret' => "...",
'consumer_key' => "...",
'consumer_secret' => "..."
);
$url = 'https://api.twitter.com/1.1/search/tweets.json';
$getfield = '?q=#hashtag&result_type=recent';
$requestMethod = 'GET';
$twitter = new TwitterAPIExchange($settings);
$response = $twitter->setGetfield($getfield)
->buildOauth($url, $requestMethod)
->performRequest();
foreach(json_decode($response) as $result){
foreach($result as $post){
echo '<div class="post"><div class="header"><img src="'.$post->user->profile_image_url.'"><p class="user">'.$post->user->name.'</p></div><div class="text">'.$post->text.'</div></div>';
}
break;
}

Answer 1

I figured it out with help from #Uwe Allner. It turned out the Twitter API has something called API Rate Limits. So, as you may guess, they are limiting the amount of requests per x time. Under "Search", I noticed they have set a limit at 180 queries per 15 minutes. So I can make a query each 5 seconds.
180/15 = 12
60/12 = 5