Sounds like you had a great trip. My wife and I just returned from the Cape (Brewster) as a 5th anniversary present. We ate at TJ's and Cobie's, both seafood and ice cream shacks on 6A. Of the two, we preferred Cobie's because it was tastier and almost 25% less. TJ's was really kinda pricey for fast food. Liked the shrimp roll at Cobie's, but the fish and chips were the best. The fish and chips at TJ's was good, too, with a huge piece of haddock and crisp fries.
We also hit Provincetown on the day of the Parade during their Carnival week. Ate at the Lobster Pot, which was highly recommended. While we thought it was OK, we weren't blown away by the clam roll or the tuna roll. We did have the tuna sashimi to start and that was tasty an the staff was en fuego on an extremely busy day.
The centerpiece of the eating was dinner at Chillingswood, the B&B we stayed at. The restaurant is renowned for its French cuisine and it didn't disappoint. The 6-course meal comes with an appetizer, salad, sorbet, the main course, a sweet course (amusements), dessert, and impeccable service. I led with two crab cakes, then had the rack of lamb encrusted in pistachios, with a chevre and fig creme brulee and broccolini. Wifey had the seared sea scallops with corn risotto, on a bed of spinach, starting off with a peach soup w/creme fraiche. We ended with three creme brulee (pistachio, mocha, and traditional) and a molten chocolate cake with corn ice cream, which is better than it sounds with the chocolate cake.