I'm sorry. That's a pretty hard place to be in. You want a hug, some comfort, and he says no. On the one hand he's tired, but hey, we all do lots of things when we're tired because they're important to do them.
Do you think you can talk to him in a quieter moment, perhaps tomorrow morning or afternoon? Explain that even if it's a sleepy hug, it means a lot to you that he does it, as a sign of support and love when you're having a rough time? I don't think a hug is too much to ask.