This is set Season 9 but Dean didn't throw Cas out of the bunker

3. Insomnia

He couldn't sleep.

Even thought the bunker was safe, and so were Sam and Dean, Castiel had been there for three days and he still couldn't sleep.

He realized this wasn't a good thing, that his newly human body needed sleep. He could feel it starting to suffer, to shut down, and yet, even though he was exhausted of both mind and body, whenever he lay down in the soft bed in the room that Sam and Dean had let him have, he could not fall asleep. Every time he closed his eyes, emotions, newly raw, would emerge, chasing slumber away. Guilt over what had happened, causing the angels to fall, ate at him. Remembering his days cold and helpless—he had hardly slept then either—and just how hard it was to be human…Castiel didn't know how he could ever be okay again. How he could ever find rest. He had destroyed Heaven, caused his brothers and sisters to fall, to lose their wings. Being human was all he deserved.

And if he didn't sleep soon, he probably wouldn't have to deal with this much longer.

He got up from his bed, sluggish, and decided to go to the kitchen to get something to drink. Perhaps something warm would aid in his sleeping ventures.

But he felt dizzy, and his body sang uncomfortably with adrenaline—the only thing keeping him going right now—and he staggered against the wall, keeping his hand on it as he padded clumsily down the hall from the dormitory wing to the kitchen.

He fumbled for the light switch and finally turned it on, flooding the kitchen with light that pierced his eyes. He winced but went over to the cupboard where Sam kept tea and grabbed a box. It seemed an unnecessary struggle to open it up and fish a small packet out and an even harder struggle to open the packet to get the teabag out, but eventually he did manage it, and went to get a mug.

He grabbed one from the table that held the coffee maker, but as he turned back around to find the kettle, a dizzy spell struck him and he gasped.

The cup slipped from his fingers and crashed to the floor.

Castiel grabbed the edge of the table and fought to keep himself from following. How could he be this weak?

"Cas?"

He looked up, nearly stumbling from dizziness again as he saw Dean standing in the doorway to the kitchen in his pajamas, a frown on his face.

"Dude, what the hell?"

"Couldn't sleep," Castiel said, sounding exhausted, even to himself. "Sorry I broke this." He swayed and before he knew it, he was stumbling again. But this time strong hands halted his descent and guided him backward toward the table and a stool.

"Whoa, you okay?" Dean crouched in front of him, one hand on his shoulder to make sure he didn't pitch off the stool.

"I'm fine," Castiel tried to protest.

"No, you're not," Dean insisted. "What's going on, man?"

Castiel sighed, propping his head up with one hand. It felt too heavy for his neck alone to hold it up. "I'm just tired. I haven't been able to sleep."

"How long?" Dean asked, frowning.

Castiel looked away from him. "I haven't slept since I got here."

Dean's eyes blew wide. "Three days? You haven't slept at all?"

"No," Castiel said in frustration. "I try, and I'm so tired, but every time I lay down everything is just too…too much. Too heavy. All I want is rest." He felt his eyes smart and blur and was surprised to find that he had tears in them. That made him even more frustrated.

Dean sighed. "Hey, I know how that is, trust me. It's hard to get those thoughts to go away, but you gotta take care of yourself, man. You're human now, and humans need sleep. Your body will quit on you."

"Then how?" Castiel demanded, feeling more desperate by the minute.

"Well, first, let me make this tea for you," Dean said, straightening up and going to put the kettle on the stove. "And we're gonna do chamomile, because it doesn't have caffeine in it." While the water was heating, he cleaned up the broken cup. Then once the water was boiled, he got a new one and poured the cup of tea for Castiel. He nodded to the angel. "Now let's get you comfortable in bed."

Dean offered a hand on Castiel's shoulder in support, carrying the cup back to the room for him as the ex-angel staggered, dragging his body back to his room.

He sank onto his bed and Dean placed the cup in his hands. Castiel took it gingerly, his hands clumsy.

"Are you comfortable here?" Dean asked, sounding somewhat worried.

Castiel nodded. "This bed is sufficient. That's not the problem."

Dean sat on the side of the mattress, clasping his hands over his knees. "Then what is, Cas? You can talk to me, you know. Sam and I are here to help. I know you're going through a lot and you probably have a lot of questions."

Castiel sighed. "I have been plagued before by my guilt, but it has never manifested so physically. Dean, what I caused…"

"It was Metatron," Dean said firmly. "You know that."

"That doesn't help me sleep," Castiel replied quietly. "And I'm afraid that if I do…all I will see is what I did. Everything horrible thing I've ever done will come back to haunt me in my nightmares."

Dean studied him for a few seconds. Castiel took a few sips of the tea and felt the warmth flow through his body. Maybe he was relaxing, or maybe his system was just finally giving out.

Dean then stood, and Castiel felt a sudden jolt go through him, a sudden fear of being left alone. But Dean only went around the bed to pull the chair from the desk over and sit in it.

"How about I stay here tonight?" he asked.

"Dean, no, you should sleep in your own room…" Castiel tried to protest, but it sounded weak, even to his own ears.

"You watched over me all these years," Dean said and it was true. Castiel had watched over Dean and Sam. Especially when their nightmares had plagued them. He had done what he could to ease them, even though he hadn't been able to stop them every time. "I think I can watch over you a couple nights. And if you have a nightmare, I'll wake you up."

Castiel was touched deeply by Dean's sentiment, and a calmness seemed to wash over his body. Relief. Something let go inside of him, a tangled knot that seemed to be unraveling.

"Thank you," he whispered, a lump in his throat.

"No problem, Cas," Dean said quietly, leaning back in the chair.

Castiel felt the pure exhaustion pull at him and he set his half drunk cup of tea aside and slumped further into the bed. He pulled the blankets up around his shoulders, feeling the warmth cover him in a comforting cocoon. He may not be able to sense Dean's soul as a human, but he could still hear his breathing and it was the only lullaby he seemed to need. He wasn't alone. Dean and Sam were there for him, and he was safe—they were all safe. And they would figure out a way to fix the angels and Heaven too.

Castiel's eyes slid shut and with a sigh of released tension, he finally slept.