I just got twitter4j, http://twitter4j.org/en/index.html ,  working and it seemed more straight forward to me. You'll have to sign up for the consumer key and auth codes https://dev.twitter.com/ . Below is the ubiquitous "sandwich" example. Once you download the twitter4j-2.2.0.zip unzip it and drag twitter4j-core-2.2.0.jar onto your sketch window. This adds the library (like import). 
  You can change:
   Query query = new Query("sandwich"); to Query query = new Query("<userName>"); and string match the t.getText . To find your text. Good Luck. -T

1. String consumerKey = "<your consumer key here>";
   String consumerSecret = "<your consumer secret here>";
   String accessToken = "<your access token here>";
   String accessSecret = "<your access secret here>";
   AccessToken token;
   
   
   Twitter myTwitter;
   
   void setup(){
      myTwitter = new TwitterFactory().getInstance();
      myTwitter.setOAuthConsumer(consumerKey, consumerSecret);
      token = new AccessToken(accessToken, accessSecret);
      myTwitter.setOAuthAccessToken(token);
    
     try{
       Query query = new Query("sandwich");
       query.setRpp(100);
       QueryResult result = myTwitter.search(query);
      
       ArrayList tweets = (ArrayList) result.getTweets();
      
       for(int i = 0;i<tweets.size();i++){
         Tweet t = (Tweet) tweets.get(i);
         String user = t.getFromUser();
         String msg = t.getText();
         Date d = t.getCreatedAt();
         println("Tweet by" + user + "at" + d + ": " + msg);
       }
     }
     catch(TwitterException te){
       println("couldn't connect: " +te);
     }
    
   }
   
   void draw(){
   }