If Severus had kept a journal, it would read like this:
By my calculations, I have worked twenty-six hours a day for several weeks. I do not know how this is possible without a time turner. The Dark Lord has returned, and he is anxious to make up for lost time. He requests potions, poisons, and information. I also have my classes to teach as well as Potter's unsuccessful Occlumency lessons. The boy has no idea what I risk by attempting to help him...
I would reluctantly accept the headmaster's aid in such circumstances, but since he is absent, I do not even have that option. Instead there is the insufferable woman sent by the Ministry with lies for these students. They aren't old enough to remember how it felt last time, yet they are smart enough to know something is wrong. I must endure Umbridge's constant scrutiny, her suspicion: "Where exactly were you last night? Why were you late to your first class this morning? Well, let's not have it happen again. Hehe."
I can see it in her eyes, and probably her mind as well if I were to look; she knows the Dark Lord is back. I am the only person here, besides Potter, who knows this for certain.
Of course, he did not have a journal because it would be dangerous for spy.
It was all true, however, Severus found himself quickly reaching the end of his rope. He couldn't say what might happen then. The only other time he'd lost control, Lily never forgave him, died hating him, and without knowing how much Severus loved her. No, now wasn't the time to think of this. He had to keep such thoughts reigned in tight, for in the Dark Lord's hands they were weapons. Too much remained at stake.
But Severus honestly wasn't sure if he would be able to continue at this pace any longer. Potions only replaced food and rest to an extent, and brewing them took time he didn't have anyway.
"Yes? What is it?" he said, snapping out of his reverie.
"My potion sort of, er, exploded." Neville Longbottom managed.
"Well, sir, it's just...you usually..."
They were all watching him expectantly. "Ah, yes, twenty points from Gryffindor. Mr. Longbottom, you have less than a muggle's chance at becoming even inept at potions. Go see if Madam Pomfrey can do something about your eyebrows." Severus briefly glanced at the clock. Sure enough, he had been very distracted today. "Class dismissed."
His students gathered their things and hurried from the classroom, talking perplexedly amongst themselves.
"Did you see that?" a random Gryffindor whispered.
"And when he insulted me, it was like his heart wasn't in it," Neville added. "I'm actually worried for the greasy git."
The door closed, and he sank into the chair behind his desk, massaging his temples. The silence was only temporary.
Knock. Knock. Knock.
"I am very busy," he announced coldly. "Leave me be."
"Severus? I'm coming in." True to her word, the Transfigurations professor swept into the room, pointy hat and all. She fixed him with a concerned expression.
"May I ask why you have chosen to invade this rare moment of peace and quiet?"
"I didn't see you at breakfast this morning, Severus, or yesterday."
"That isn't particularly surprising, Minerva, as I was not there."
"Have you been eating anything?" she demanded.
"Yes. A house elf brings my meals and I eat while grading papers. When I cannot, there are potions to supplement nutrition. Does that answer satisfy you?"
"I just worry," Minerva sighed. "It isn't easy for anyone with that horrible bitch in charge, and Albus away from the school. These are difficult times we face. You should know that I, at least, trust you."
"Because Albus trusts you."
"That's hardly a reason." he replied.
"It's enough for me, and for the Order," Minerva said.
Severus didn't respond immediately; the Dark Lord was summoning his followers. He gripped his left forearm, but the Mark only burned more painfully. "I have to go, Minerva."
"All right," she allowed, smiling slightly. "Just...try to get some sleep tonight, please. Students are saying that you are losing your touch."
This was bad news. The very last thing he wanted was not to be feared.