Hi!
I �ve been in your situation before but my students had a substitute teacher, so I didn �t have to start from scratch.
I would probably try to do a re-introduction activity with them, maybe by asking them to choose a few adjectives to describe themselves and then they would have to say whether they agreed with their classmates description.
I would do a short round-up with all the classes, too, in order to see what they may or may not have forgotten and I would move on from there.
These are really basic activities, which normally work well but let us see what other teachers have to say.
I �m glad you �re feeling better now, that �s the most important thing.
Have a nice day!
Georgina