I know someone who has some intense struggles
He lived with friends for a while after he could no longer live at home, and, during that time, he had a couple of incredibly strong spiritual experiences - after first deciding to listen to the missionaries because both sister missionaries were "absolute babes". (What can I say; he was 18.) He is highly intelligent, and he "got it" very quickly. He and I had some long talks, and he really did have some awesome experiences and insights. He was baptized while living with his friends, then left for college a few months later.
He had some negative experiences in his new ward that don't need to be detailed here. As a result of those experiences and the subsequent lack of the type of support system he had when he joined the Church, he began to return to the life he had lived prior to coming to that. His dysfunctional adolescence caused some very deep habits and inclinations, and, left on his own, they resurfaced. I have prayed for him and hoped for him, but I have seen his actions take him away from activity in the Church.
He returned home once for the summer, and his father mocked his inactivity by saying something like, "I guess that Mormon thing isn't working out for you." His response gave me hope in the midst of my concern. He said to his father, "I'm not living the way I should be living, but the Mormon Church is still the truest thing I've ever heard. I just have to get myself together before I can live it."
I hang onto faith that "when he is old, he will not depart from it". I KNOW his experiences and insights were real; he knows they were real. I have to trust that God's mercy truly will save him from the results of Adam's transgression in his life - and I see the issues that are keeping him from full activity directly as a result of what he inherited from his parents and what he had to "become" to cope without killing himself.
I believe the Atonement is MUCH more powerful than we often realize. Surely, God understands those whose struggles overwhelm them, and we someday will "stand all amazed at the love Jesus offers (them); confused at the grace that so fully he proffers (them)."