I didn't have time to read all what has gone before but, if you're going for a few days and have a vehicle to lug it around in (I don't know how mobile you'll be or if you're just static fishing), I suggest:
- Wet wipes or even an old towel/ T-shirt/ rag for cleaning things.
- A fleece cover, cloak or something warm to wrap up in when sitting. Not a blanket but something lightweight but warm and snug.
- A torch is a must if you're camping nights but what is more useful is a full lamp - either LED or not - something to light up a camping plot efficiently.
- WATER!!! Can't stress this enough, unless you have a source of fresh stuff on site.
- Change of clothes in case things get wet, and on that matter, a waterproof jacket or at least an umbrella, but I guess that'll be in on the fishing items list.
- Tools: pocket knife, axe or hammer, Swiss Army knife. I never leave home without tools and you wouldn't believe how often I use them in daily life!
- Disposable cups, plates, forks or whatever if you aren't taking the real things.
- Clean underwear!!! I'm doubting you'll have access to a shower so in that instance it's at least nice to have fresh undies to put on everyday. You could also use the wet wipes for a wash if you get all grubby.
- Some soap of some sort to wash face and hands.
If I think of anything else I'll edit it in.
Enjoy your trip. Camping is great fun.