Low cal filling food options besides meat?

What's filling is going to be somewhat individual. Did you figure out that meat was filling for you by experimenting with various options, and settling on that? Expand the range of experiments.

How far have you cut calories to lose that 5 pounds? Trying to lose too fast can make the problem unsolvable. With 5 pounds to lose, I'd recommend shooting for half a pound a week loss (or slower), which would be a 250 calorie daily deficit (or smaller).

I haven't eaten meat since 1974 . . . and I'm not frequently hungry. (I don't think it matters, but I do weigh 130 pounds.)

I do find protein filling, but also volume. On the protein side, some filling but lower calorie things are Greek yogurt, cottage cheese, hard boiled eggs, beans, dry roasted soybeans or crispy chickpeas/broad beans. I find oatmeal with berries and Greek yogurt especially filling. For volume, it's usually large amounts of veggies and fruits: I routinely eat 800 grams (1.75 pounds) of varied veggies/fruits daily.

Some people find fats filling. If that works for you, nuts, nut butters, avocados or cheese could be good choices . . . in reasonable portions, because fats are calorie dense.

In research, one of the commonest foods people found filling was baked potato. Potatoes are nutrient dense, and not that high in calories for the nutrition. (It's the usual toppings that add the calories.) Whole grains are another possibility: Wheat berries, brown rice, that oatmeal or steel cut oats, barley, etc.

Timing of eating may matter, too. People feel most satisfied on anything from one meal a day to all-day small-snacks grazing, and everything in between. That's another thing to experiment with.

For me, the overall filling pattern is a solid breakfast with plenty of protein, then protein through the day; plus at least one meal with high volume (usually the fruits/veggies, and usually dinner). If I start feeling hungry when a meal isn't coming up soon, it works better for me to have a small snack, usually something with protein, but occasionally fruit/veggies. (Some other people do better if they stick to 1, 2 or 3 meals with no snacks.)

Best wishes for figuring out your personal formula!