Nothing we can do is terrible that it cannot be washed away with the blood of the Lamb. No matter how far down the path we go, we can always turn back and climb upwards. The Lord has promised us this and He never breaks His promises. Who are we to question Him or deny His word? It is pride and foolishness that tell us we are the exceptions to His rules, that we are too broken for Him to fix us. If you put a limitation on yourself you put a limitation on the Lord's power. He has no limits on His power, there is NOTHING He cannot fix, and NO ONE He cannot save if they will turn to Him. We have to take that first step, but He will not leave us to walk alone, we will never walk alone.
I echo Elder Perry's sentiments that Jesus is the Christ. I know that the scriptures are true and they will lead us to true happiness. Test our words, read the Book of Mormon, pray to the Lord, what harm can it do? None, it can only bring great joy and happiness into your life as it has brought it into mine. The Lord loves you and is waiting for you to come unto Him and be perfected.