Dear one -
Allow me to take a slightly different tack from the very sound advice already given.
First a touch of background. I left the practice of the faith at 18 and did not return for 35 years. In that time, I would say that I covered pretty much everything that you mention in your post, and have to deal with the reminders of those sins on a regular basis. So I can definitely understand where yo are coming from…It’s even more profound for me in some ways, since one of the greatest blessings in my life came to me through a great sin. But that is another story altogether.
Anyway - to your question…How does one get over one’s bad past?
Not by “forgetting it” that is for sure. These things are part of our memories and the recollection of them can bring forth many strong emotions. Someone above said that God forgets our sins once they are forgiven…well - maybe that is true and maybe it isn’t, I just know that
I don’t forget them. So the question then becomes what to do with them.
The understanding that I have come to is this. Getting over a bad past is not about “forgetting” it. Rather it is about putting it into proper perspective. It is about learning the correct lessons and then being able to apply those lessons to our current life and/or use those lessons in offering advice to others. Not that you share details of your past sins, but rather you let others know that you understand because you’ve been there yourself. Sort of like I did above.
There is an axiom in the military that one learns more from defeat than from victory. As a result, in military training, past battles are studied more for what was done wrong and how to improve than for what was done right.
At confirmation we were told that we were becoming soldiers for Christ. If that is so then the recollections of our past sins may well be a tool of the Holy Spirit. A tool used to teach us and to guide us so that we never go back to that and also that we might be better able to help others in similar situations.
Where such recollection becomes problematic is when one either does not understand the proper role that such recollection plays, or when one has not been able to accept the forgiveness offered to us in confession. In short, there needs to be a proper balance and understanding.
Think of it like this. A man commits a crime, realizes it, repents, turns himself in and goes before the judge. The judge, based on the man’s obvious contrition, is very lenient in his sentencing. The man completes his sentence and moves on.
Has the Judge taken away the man’s guilt? No - the man remains guilty of the crime.
What has been added is forgiveness. He repented, served his time, and can now move forward with his head held up.And so it is with us. We remain “guilty” for our past sins. But we have also been “forgiven” and our past sins will not be “held against us”.
The devil might try to convince you otherwise, but it simply is not true.
So - after all of that, what is my advice?
Recognize that you are forgiven - even if you sometimes feel “unforgivable”.
Recognize that recollection of sin can be a means of protection against backsliding and an impetus to greater growth in holiness.
Use this knowledge of both guilt and forgiveness to become the best and most loving “Child of God” that you can be.
I hope this is of help to you.
Peace
James