Castiel could probably indulge his want to crawl into bed and hold her, if for a little while. Because he hadn't slept as well as he could have while he and Meg were apart, it would possibly even do him well in the long run. But, he wouldn't push his luck. Just because she was crawling under the covers and looking to sleep off the alcohol, it didn't mean that he was welcome to join her. He would just play guard, watch over her in case she needed something. He would be her care taker for a change, because it wasn't often he was placed in that position and it was one he would take without issue. He loved her and wanted to take care of her, simple as that. If it helped make her even just the slightest bit 'better', then he would take it.
"No, of course not," he told her immediately, because the last thing he wanted to take back was admitting their love for one another. It had taken him a while to stumble upon those feelings and while he was uncertain if the same could be said for Meg, he didn't want to take back that discovery. It was important and to take that back, it would put him back in that place where he'd been so unsure of what to do around her.
He moved to sit on the edge of the bed, watching her carefully, because he was trying to figure out what to do. He was feeling his way through this, hoping he wouldn't say or do something that would make Meg withdraw from him again. He had no idea how messy things actually were between them, because he didn't have a proper gauge of relationships, especially not those of the romantic nature. He could never claim that his relationship with the Winchesters was considered cut and dry and it was never of the nature of what he shared with Meg, so he couldn't compare the two.
"Would you like for me to stay?" He asked this, because he didn't want to hover here, if it was unwanted, his presence. It would hurt, knowing she didn't want him around right now, but he could manage. He still had to go to town, after all. But he hoped she would say yes. That she would allow for him to stay with her.