portion size?

Get a food scale, weigh everything.

At least half of Whatever your meal/snack is should be fruits or vegetables just go with your caloric limit from there.

This morning I had 3 homemade whole wheat pancakes (14 grams of protien) topped with baked apple slices (no added sugar just on whole apple) and half a large orange with a half a cup of strawberries

or Another breakfast I had was

2 eggs with half an avocado and a handful of cherry tomatoes.

For Dinner I usually just have 3oz-5oz of Salmon and fill the rest of my plate with veggies if the salmon fillet is on the small side some time's I'll add a little bit of mashed sweet potato. Same with chicken just a single grilled breast and a lot of steamed vegetables.

For things like pasta I normally don't eat any more than 1 1/2 cups.

In general I just make sure approximately 50% of what I eat is fruit or veggies. I try not to eat a lot of fruit after lunch because otherwise that's all I end up eating. The other stuff is really up to you I think as long as the other things are healthy foods like whole grains and lean meats. This way you only have half a plat to work with so it's really hard to go over bored. At least in my opinion. This is what works for me. I hope you find what works for you soon.