Fourteenth Rule. The fourteenth: Likewise, he behaves as a chief bent on conquering and robbing what he desires: for, as a captain and chief of the army, pitching his camp, and looking at the forces or defences of a stronghold, attacks it on the weakest side, in like manner the enemy of human nature, roaming about, looks in turn at all our virtues, theological, cardinal and moral; and where he finds us weakest and most in need for our eternal salvation, there he attacks us and aims at taking us.
I don't know why but this rule sticks in my head the most...I find it coming to mind when I am tempted or having desolate thoughts: the attacks are effective because the one attacking knows what he is doing. But no matter how wily or canny he is, he doesn't win! And no matter how weak we are, God is giving us the strength to continue on. We shouldn't be surprised to find that suffering hurts or fears make us scared or temptations lead us toward wrong things that we really do want to do...the enemy is real, he is artful, and he's been doing his job for thousands upon thousands of years...so basically he is good at what he does. But God is stronger and he's there whether we feel him or not, which means that even in our weakest moment...we're okay.
So get to work: identify those desolate thoughts. Pray and make sacrifices within your scope, tell a trusted spiritual friend and be patient. Heaven is worth it. And God loves you.