Ishie,
Way to go!! You should be proud that you acted and had taken the steps to have the knowledge to act. I wish more people would take basic first aid and CPR.
I can understand the feelings that you are experiencing. I've been in similar circumstances. You did what you could! You'll never forget that child, but you should be able to look back on the situation and know that without you, that child wouldn't have had ANY chance. You gave her a chance, things unfortunately didn't work out, but you did what you could!!
You rock!