The street hotdogs in Iceland are surprisingly good. Also, if your room has a fridge, head to a store and stock up on cheese, bread, sausage, and other edibles. You’ll save $$ there. Also, most hotels include breakfast. Stuff yourself at breakfast, so you can eat just a light lunch, like a hotdog or your cheese and crackers, so you’re only spending money to eat dinners out.
If you didn’t pack warm clothes for the unpredictable Icelandic weather, consider splurging on a lopapeysa, the traditional Icelandic sweater. They are expensive, but wonderfully warm. If you don’t want to pay full price for a new one, there are some good thrift shops in Reykjavik that frequently have a decent selection. I picked up a lined, zip up hooded one for about $100. It’s amazingly warm and looks nice. I wear it all winter.
You sound a bit tired. I’m hoping that a good night’s sleep and some of your tours will help. Don’t know if you’ll get a chance to visit the Blue Lagoon or one of the other natural hot springs, but sipping a cold Viking or Gull beer while relaxing in the beautiful milky blue mineral water will ease a lot of travel travails.
