hi
go back to where you feel you could comfortably pick up - try week 3 but if that feels too hard go to week 2. Don't feel that you have gone backwards - being ill for 2 weeks can take it out of you and you need to start back slowly
stitch - I have never had trouble with it, but maybe you need to go slowly. had you eaten or drunk anything different?
Also, it is a lot warmer today than it was 2 weeks ago (where I live anyway) and it is always harder in the heat, I struggled this afternoon