Need a help with apex trigger problem solution

with 3 custom fields:

1) Lookup to user object.
2) Number of open task (number field) 
3) Number if closed task (number field)

When a task is created by user A with let's stay status is IN PROGRESS, I need to create record in Task Tracking object record with these details :

1) Lookup field = user A
2) Number of open task = 1 
3) Number of closed task = 0;

Now next time, when same user A creates another task, the new Task Tracking record shouldn't be created but it should only increment/decrement Number of task field.

I have tried this much. I was able to create Task Tracking record whenever a Task is created but It was creating new Task Tracking Object for every Task that I am creating

trigger TrackTask2 on Task (before insert) { 
List<sujya__Task_Tracking__c> li = new List<sujya__Task_Tracking__c>(); 
sujya__Task_Tracking__c s = new sujya__Task_Tracking__c();
if(Trigger.isBefore && Trigger.isInsert){
 for(Task t:Trigger.new)
{
 s.sujya__User__c = t.CreatedById;
 li.add(s); 
} 
insert li; 
}
 }

Appreiciate your help :)