Avocado is very filling. Just tonight actually I made a salad with avocado, corn, and some other veggies in and vinegar dressing, no meat. Corn is a grey area for some people on paleo but I think it's good filler calories.

Beans are another grey area. Honestly we still eat a lot of beans, I love black beans! And lentils. If they don't bother you and you really want to cut out meat then beans are good protein and fiber.

You don't need to eat meat 3-4 times a day by the way. My breakfast is often vegetarian and sometimes vegan, sweet potato hash is a great option, and smoothies. And we end up eating vegetarian meals a few days a week, usually big salads of some sort or heavy soups... I could live off potato soup haha.