Thank you again for your last corrections!

Question

Can you help me check these sentences please?

1) I had planned to do a lot of things during my Christmas holidays but unfortunately I didn't get around to doing them all.
( and NOT I had no time to do all of them)
2) I decided (?) to rest after the hard work at school (and NOT the stress accumulated at school?)on my first days of holiday
3) On Boxing Day I left for "St Moritz", a ski resort in the Alps where I celebrated New Year's Day with my friends
4) I stayed there till January 28.
5) Eventually,it was a good Christamas (OR All in all, I spent a good Christmas time or I enjoyed my Christmas holidays)
6) How are the possible prepositions with "Christmas holidays"
During/on/over my Christmas holidays I stayed at home (in my IS WRONG?)
7)On Christmas Eve I exchanged Christmas greetings with my relatives and we had dinner together.It is a tradition of (in?) my familiy because Christmas Eve is the day of my aunt's birthday.
8) On Christmas Day I stayed at home because I was ill and I went to bed right after midnight.
9) I finished my homowork on January 7 as I did not want to do any homework on the day before school began (or on January 8)
10) When the teacher saw the blown bulb, he got frightened and urged us to go(?) under our desks. A few minutes later he told us to go to our places and he continued his lesson again. (Is this version better?)