Four suggestions:

1. I agree that your carb count might need to be lower, like under 40 g
per day, as in
"induction" phases of the low-carb diet plans. This amount would be
temporary until weight loss is achieved, then it could go up to a
"maintenance" amount, which may be the amount you're doing now

2. I think the satiety factor with the tuna/olive oil vs. red
meat/saturated fat might also be the protein selection. Red meat has
more purines, which some people need to get sufficient energy. I am a
fast-oxidizer metabolic type and I do best with high-purine meats
(dark, organ) and high-purine veggies too, but the meat is most
important. I could eat a low-purine light or white meat with lots of
fat and be hungry in an hour.

3. Some people go into a weight loss stall because they are eating an
allergic food. I don't know how this mechanism works, but I've heard of
it and also experienced it. I don't lose weight while drinking black
coffee because I have some kind of intolerance to the coffee. So I just
won't lose. As soon as I quit the coffee I start dropping. I've heard
of this phenomenon with many other people, with varied foods (like
dairy, eggs, and other commonly allergenic foods).

4. Some people do VERY well adding a Carnitine Tartrate supplement.
Studies have shown good results with how it increases weight loss -
Robert Crayon who wrote the "Carnitine Miracle" and also is pro-paleo
has a lot to say on the benefits of supplemental Carnitine- has to be
Tartrate form though, and is expensive. I've seen people get great
results on it.

good luck

Laura