Why can't i get my past sins out of my thoughts?

Why should you be able to get them out of your thoughts? You won't. Even if you are forgiven, you are not going to forget your sins. They should remain, and the shame of them, to keep you from repeating. Know what I'm saying?

Once you've accepted that God has forgiven you then you need to work on forgiveing yourself. It takes time to heal the mind of flashbacks and memories of wrongs that you've done but you need to work on conditioning your mind, it will happen less and less. First start with the emotion of it then work on forgetting and try building up some new memories better ones I guess it could be sacntification where you replace 5 bad things with 5 good ones. When you catch yourself thinking about it don't feel bad anymore and move on to the next thought a more positive thought. Knowing joyfully that God has already forgiven you now embrace that fact!

because u haven't forgiven ur self for them.. just think back about what it is u have done n just forgive urself.. or if u believe in god.. then ask him for forgivenss.. then just try to move on from there.. n think how those things made u a stronger person..

Maybe you haven't come to terms with what you did, and why? Facing things is really hard, but it's got to be easier than having it keep popping up in your dreams, day and night.

You can forgive your self over and over but the thoughts will remain in your head forever its not a matter of forgetting its amatter of living with it .. its your brains way of saying if you were of sound mind when you did the bad things then you must pay with memories of it forever but then if in fact they are memories of some one hurting you then you can forgive them but still then again you will never forget.. sad but this is just the way it must be but maybe in time it can get a little easier....

as many other people here have said, part of it i think is that you need to forgive yourself, learn and move on.
i also think people have a habit of not accepting their own mistakes in that they feel less than the person their perceptions want them to be.