Don't waste your time being upset about something you can't change.... The one thing in life we can not change is the past. So begin today and do it better this time... You can not change where you are right at this moment but you CAN change where your life is going to go. You are where you are today due to the thoughts, actions and reaction you had in the past. If you want to change anything in life you have to start today --RIGHT NOW-- and change your thoughts, actions and reactions. It's not as hard as people make it out to be. Everything we do is habit. You started a habit so you can change a habit. You can never stop a habit unless you replace it.
Where are you today in life? Think of the decisions you made in the past because that is what got you where are you today. Now think of the future... if your today is exactly the way you want the future then keep on thinking and doing what you are doing. But if you want change then you need to start today and NOW.