Dear all, below is my code which auto follows accounts when a new custom object KTT is created or updated. Code works fine on single record but I`m having trouble in bulkfying this code. I get "System.LimitException: Too many DML rows: 10001" error when I try to insert records in bulk via data loader. Is there something wrong with my code? I`m new to Apex world so it would really help if someone can point me to right direction.

Also, if I try to remove last few lines of DML statement, I get "System.DmlException: Insert failed. First exception on row 0; first error: DUPLICATE_VALUE, duplicate value found: <unknown> duplicates value on record with id: <unknown>: []" error.
 

trigger RTTAutoFollow2 on RTT__C (after insert,after update) {


            List <EntitySubscription > NewFollowers = new List <EntitySubscription > ();   

                            List<Id> whatIds = new List<Id>();
               
   for(RTT__C sampletracker : trigger.new)

                         {
                whatIds.add(sampletracker.Account__c);
                             }
    
Map<Id, Account> Accounts = new Map<Id, Account>([SELECT Id, Name from Account WHERE Id in :whatIds]);
             

for(RTT__C sampletracker : trigger.new){  

              
                  if(sampletracker.Account__c != NULL){ 

 
           String Accid = sampletracker.Account__c;           
            String AccIds = accounts.get(Accid).ID;                  

    if (sampletracker.No_longer_Key__c == False)
{
  
               EntitySubscription ES = new EntitySubscription();    
               ES.SubscriberId = sampletracker.Assigned_Sales_Team__c;  
               ES.ParentId = sampletracker.Account__c;  
    
           }  
  
           try{  
                insert NewFollowers;                 
           }  
           catch (System.DmlException e){  
           }  
}
}}