I endorse all the advice given above, I thank everyone who answered because I, too, suffer from scrupulosity. I would like to add that one way to cope with this heavy weight is to completely abandon oneself to God. It is an exercise in Trust. Everytime you have these feelings of overwhealming guilt and fear of condemnation say, “Jesus I trust in You.” or “Sacred Heart of Jesus, I believe in Your love for me.” Sometimes I say, “Lord, I can’t do this by myself. I need You to do it for me. I give myself to You, body, mind and spirit and beg You to transform me according to Your will. Jesus, I trust in You.”
Romans 8:28-38 has always been a great comfort to me when I feel particularly afflicted.
We know that God makes all things work together for the good of those who have been called according to his decree. Those whom he foreknew, he predestined to share the image of his Son, that the Son might be the first-born of many brothers. Those he predestined he likewise called; those he called he also justified; and those he justified he in turn glorified. What shall we say after that? If God is for us, who can be against? Is it possible that he who did not spare his own Son but handed him over for the sake of us all will not grant us all things besides? Who shall bring a charge against God’s chosen ones? God, who justifies? Who shall condemn them? Christ Jesus, who died or rather was raised up, who is at the right hand of God and who intercedes for us?
Who will separate us from the love of Christ? Trial, or distress, or persecution, or hunger, or nakedness, or danger, or the sword? As Scripture says: “For your sake we are being slain all the day long; we are looked upon as sheep to be slaughtered” Yet, in all this we are more than conquerors because of Him who has loved us. For I am certain that neither death nor life, neither angels nor principalities, neither the present nor the future, nor powers, neither height nor depth nor any other creature, will be able to separate us from the love of God that comes to us in Christ Jesus, our Lord." (NAB Romans 8:28-38)
Once, I was utterly convinced that I was going to die on an overseas journey and in a real state crying and fearful that I would die in my (mortal) sins. The Lord came to me and wrapped me in his Love and He said, “Do not be afraid. It doesn’t matter. Alive or dead, you are Mine.” He didn’t tell me that I wasn’t going to die, he told me that it didn’t matter. I repeat this to you now - it doesn’t matter. He knows your heart, how you are trying so hard to be true. You do not have to be perfect now, in this life, even though you are expected to try for it. God has chosen you, He has called you and He has justified you and - alive or dead - you are His.
The only other advice I would have would be to add the Chaplet of the Divine Mercy to your devotions, perhaps read the Diary of St. Faustina and meditate on God’s mercy.
TRUST in his promise. HE promised (you are not relying on yourself), and He is God and God does not lie.