Vegetarian for 2 years, I get sleepy in the afternoons?!

Good vegetarian sources of iron:

Baked beans (135g, less than half a can provides 13% of a woman's iron RDA for the day)
Bran flakes (40g bowl provides 66% of a woman's RDA)
Tofu (100g supplies 24% of a woman's RDA)
Kidney beans (90g provides 12%
Spaghetti
Brown rice
Curly Kale
Broccoli
Sesame seeds
Pumpkin seeds (seeds are very nutritious and make an excellent snack)
prunes
Figs (Just three dried figs provides 17% of a woman's iron RDA)
Dark chocolate (Three cheers chocolate is good for you hooray lol! But obviously the sugar not so good, so if you eat dark chocolate for iron don't eat too much refined sugar in other ways).

Its unlikely you are not getting enough protein, most western diets are too protein rich, protein deficiency is usually seen in third world countries. Perhaps look into non-dietary causes of your sleep issues, use google it might help you.

pizza and burritos- white flour? Will basically kill your energy, you may as well shoot glucose into your veins.

You can't eat white flour. Any pizza crust or white flour burrito with massively processed sauce, cheese, is gong to make you fall over with tiredness. It gives you nothing except a huge block of white refined flour to wade through.
YOu get a huge amount of white rfined carbohydrate and no live food- no vitamins or energy, just
a white paste. You may as well eat cement.

Your body has to work so hard to make insulin really quickly to get through all the white flour glucose and with NO vitamins in it to at least boost the activity inside your digestive system, you're going to keel over in a slump.

Take dried fruit, fresh fruit, yoghurt or peanuts, almonds, walnuts , raisins, ginger, peanut butter or almond butter and ONLY 100% wholegrain pita or bread- buy some this weekend and take with you and store someplace.
Take a few cans of chickpeas or a pot of hummous and the wholewheat pita . Buy bulk seeds and nuts- or a wholefood granola- with oats, honey, nuts, seeds, WHOLE ingredients. In fact the granol way would be good- Take small cartons of soymilk to add to it, and eat that.

First tell us what you are eating during the day?

Are you eating a lot of starch/carbs ro sugary snacks?

Or drinking a lot of caafiene in the mronign that could be casuing a crash?

Before just addign iron get your blood tested. That will help you figure out what is going on.

I used to always get sleepy around 3pm. Turns out I wasn't getting enough sleep at night. Try to get 7-8 hours of sleep, and eat whole foods, not sugary things or bleached flour.

It is NOT unusual for someone to get sleepy in the afternoons.