Sorry this has gone unanswered, nut allergies can be stressful, but at the same time something you also get used to over time. How allergic is DD if you don't mind me asking? Do you have EpiPens?
You will get used to reading food labels, and then reading them even of you think you know as factories change and as a parent you need to be sure. However, more and more supermarkets have nut free production sites, some better than others. Tesco for example in my experience is dreadful, Waitrose better.
Eating out is OK once you get to know the restaurants, talk to the staff, make sure they understand the gravitas of the situation. We managed a few days as Disneyland Paris with translated allergy cards and they fell over themselves to make food that was 'safe'.
Have you joined the anaphylaxis campaign? they are great and send out regular alerts etc. There are pre-prepared foods that are nut free, you just need to get used to the supermarkets, who does what, who is better and which you can best work with.
Its not a life sentence, more and more is being done with desensitization and more progress is all good. Stay on this board as there are loads of helpful people here.