hello - I have class that adds the Lead ID to a custom object. However, it adds the same ID to very lead when I do a bulk upload because of this line: ldsubs.Lead__c = listOfLeadsSubIDs[0];

I can't figure how how to add the corect Lead Id to every lead inserted via bulk insert. Any assistance would be greatly appreciated. 

public class AddLeadSubmissionToLead {
    
    public static void addLStoLead (List<Lead> leadsFromTrigger) {
        
        Set<String> nameCompany = new Set<String>();
        List<Lead_Submission__c> listOfLeadsSubs = new List<Lead_Submission__c>();
        List<Id> listOfLeadsSubIDs = new List<Id>();
        
        for(Lead nwLead : leadsFromTrigger) {
            listOfLeadsSubIDs.add(nwLead.Id);
            nameCompany.add(nwLead.LastNameStreetAndZipCode__c );
        }
        
        List<Lead_Submission__c> ldSub = [SELECT Id, Lead__c, LastNameStreetAndZipCode__c
                                          FROM Lead_Submission__c 
                                          WHERE LastNameStreetAndZipCode__c =:nameCompany];
        
        System.debug('Lead Submission Found ' + ldSub);
        
        for(Lead_Submission__c ldsubs : ldSub) {
            if(ldsubs.Lead__c == null && !ldSub.isEmpty()) {
                ldsubs.Lead__c = listOfLeadsSubIDs[0];
                listOfLeadsSubs.add(ldsubs);
            }
        }
        update listOfLeadsSubs;
    }
}