Roll Up Summary using Trigger

trigger sumofLPT on loan__Loan_Payment_Transaction__c (after insert, after update, after delete) {
    List<loan__Loan_Account__c> llaList = new List<loan__Loan_Account__c>();
  
    Set<ID> setlpt =  new Set<ID>();
  
    for(loan__Loan_Payment_Transaction__c lpt: trigger.new)
    {
        setlpt.add(lpt.id);
    }
    Decimal sum1;
    Decimal sum2;
    Decimal sum3;
    Decimal sum4;
    for(loan__Loan_Account__c loan: [select name, (select name, loan__Cleared__c, loan__Rejected__c, loan__Rejection_Reason__c, loan__Reversed__c, loan__Reversal_Reason__c, loan__Transaction_Amount__c FROM loan__Loan_Payment_Transactions__r)
    FROM loan__Loan_Account__c ])
    {
      
        sum1 = 0;
        sum2 = 0;
        sum3 = 0;
        sum4 = 0;
        for(loan__Loan_Payment_Transaction__c lpt1:loan.loan__Loan_Payment_Transactions__r){
        if(lpt1.loan__Rejected__c == true){   
            sum1 += lpt1.loan__Transaction_Amount__c;
            loan.Rejected_Transaction_Amount__c = sum1;
            System.debug('!!!!!!!!!!!!!sum1'+sum1);
            System.debug('@@@@@@@@@@@@@loan.Rejected_Transaction_Amount__c'+loan.Rejected_Transaction_Amount__c);
          
           }
            /*else
            {
                for(loan__Loan_Payment_Transaction__c lpt2: Trigger.old){
                if((Trigger.isUpdate || Trigger.isDelete) && lpt1.loan__Rejected__c == true){
                loan__Loan_Payment_Transaction__c lpt1old = Trigger.oldMap.get(lpt1.Id);
                }
               }
            }*/
         if(lpt1.loan__Reversed__c == true){
            sum2 += lpt1.loan__Transaction_Amount__c;
            loan.Reversed_Transaction_Amount__c = sum2;
            System.debug('!!!!!!!!!!!!!sum2'+sum2);
            System.debug('@@@@@@@@@@@@@loan.Reversed_Transaction_Amount__c'+loan.Reversed_Transaction_Amount__c);
            }
         if(lpt1.loan__Cleared__c == true){
            sum3 += lpt1.loan__Transaction_Amount__c;
            loan.Cleared_Transaction_Amount__c = sum3;
            System.debug('!!!!!!!!!!!!!sum3'+sum3);
            System.debug('@@@@@@@@@@@@@loan.Cleared_Transaction_Amount__c'+loan.Cleared_Transaction_Amount__c);
            }
            if(lpt1.loan__Cleared__c == false && lpt1.loan__Reversed__c == false && lpt1.loan__Rejected__c == false){
            sum4 += lpt1.loan__Transaction_Amount__c;
            loan.Uncleared_Transaction_Amount__c = sum4;
             System.debug('!!!!!!!!!!!!!sum4'+sum4);
            System.debug('@@@@@@@@@@@@@loan.Uncleared_Transaction_Amount__c'+loan.Uncleared_Transaction_Amount__c);
            }
        
        }
        llaList.add(loan);
    }
    update llaList;
  
}