Welcome to the forum!
Peanut butter is definitely not paleo. Peanuts are legume, full of antinutrients and bad fats. Then to make it even worse, most peanut butter is hydrogenated and has sugar added. If you must use a nut butter, use something else, but too many nuts isn't a good thing as you already found out.
On paleo you should never have to feel hungry. If you are hungry, eat something! Just make it paleo. And make a mental note that next time you need a bigger/fattier meal.
Meat is your friend, especially fatty meat. It is very hard to overeat meat, as you start to feel sick when you've eaten to much, but at the same time if it's a fatty piece it's very sustaining. Things like slow-cooked beef or pork ribs or lamb shoulder are very satisfying. 70% beef mince is versatile and has a decent amount of fat in it. Go for grass-fed if possible.
Sweet potatoes are considered primal but not paleo. Some people eat them. I eat them as an occasional vegetable, but not as a major source of calories. If you're not in athletic training and trying to lose weight it's probably better not to eat them.
Base your meals on meat or fish with non-starchy vegetables, and keep making the meals bigger and/or fattier until you no longer get hungry. If it's a fish meal, a good way to make it more sustaining is to cube up a tray of veges eg carrot, parsnip, beetroot, zucchini, and roast it in beef fat.
