Don't beat yourself up about it - 2 lessons since Xmas is nothing really. Try and book some time off work to get a bit of continuity if you can - it helps so much in the early lessons and will save you money in reworked lessons later on.
If you're feeling down because your instructor is one of those nagging / hectoring types, try someone else who has a more coaching / mentoring style and which you feel more relaxed with, remember you are the customer in all this and it should be fun!