Chapters 10-12 are all one unit; 10 introduces the set.
Daniel was in mourning, fasting and praying for three weeks. (v1-3)
Evidentally he was praying to know what would happen to his people, v12,13 "since the day you set your heart on understanding this...but 3 weeks i've been detained"
Note on prayer:
daniel spent three weeks in prayer.
that's quite a bit of persistance.
When...all of a sudden, a being in linen that only Daniel could see appeared! (v4-9)
The angel then twice encourages Daniel to understand the vision. (v10-21)
Daniel lost his strength due to the vision (v9), then fell asleep when he heard the words (v9)
An angel then touched him and set him 'trembling on [his] hands and knees' (v10). The angel then encourages him and tells him to stand up (v11).
After the angel spoke, Daniel turned his face toward the ground and couldn't speak. (v15)
An angel then touched his lips and Daniel spoke (v16)
Now that Daniel can speak, he says that he's has no strength/breath (v17).
The angel touches him again and strengthens him again (v18).
Finally, it's the angel's turn to talk about how tired he is; he is going to go back and fight the prince of persia, and none helps him except michael.