Everyone regrets something they did in their lives, some things we can let go very easy but there always that one thought or happening wich can give negative emotions. 

Rember those things are happening for your own spiritual growth. It is forming you as the person you are today. And deep down you know it mabey already. You won’t make the same mistake twice is a simple but a good example. 

Even when you stil keep thinking or over thinking about it, don’t worry and please try not to be
so hard on yourself, seeing something good in a bad situation is asking some time. You Will get there
as long you take good care for your mind and body and remember to send positve thoughts in
the  universe.