I am scrupulous aswell. If you ask me, the best way to deal with scrupulosity is to get help.
As I understand it, the best way to do this is by finding a regular confessor and then talking to him about your doubts (for example if a particular sin is mortal or venial).
And then the most important thing is being obedient to what that priest tells you (for example, if he tells you that it is or isn’t mortal).
The key is that you do as he tells you, because his guidance and obedience to his guidance will bring healing.
Perhaps my example will help you in doing this, so that you wouldn’t repeat my mistakes:
I found it very difficult to tell anyone in person that I was scrupulous and to ask for guidance.
So I tried to “handle” it on my own, by trying to find answers about morality (eg., if some of my sins
were venial or mortal) online (catholic forums, spiritual books…).
And the more I read about it and the more I was thinking about it and the more I was trying to figure
out whether I was fully aware in a particular sin, whether I consented or not,…, the more my scrupulosity grew and became worse and worse.
Until it “outgrew” me and took control of my life and actions (I was begining to doubt whether some of the most normal things I did were sins or mortal sins).
So one day, reading through the internet that I should go and ask for help, I decided to do exactly that. To be brave and do it, even though I was ashamed, afraid and felt like I didn’t know how to do it, or that I am not strong enough to do it.
I ended up asking a priest I know for a conversation (outside of confession). And he agreed. Since then we talked several times, i told him a lot about my scrupulosity, he explained a lot of things to me and gave me some firm direction, and told me to be obedient to that direction.
And being obedient to that direction (no matter how much my scrupulosity has been telling me not to be obedient to it) has already brought healing and I hope will bring much more.
This priest is starting to become a spiritual director to me, and i am thinking about making him my regular confessor aswell.