Okay. You already went the mineral foundation route and got no where so it seems like you would do better with a "wet" foundation, but not one that will be heavy on your face or you'll find it "sliding" off before the end of the school day.
I would suggest a good face primer. Everyone has a different opinion about the brand. It is all about how much you are willing to spend. Your skin type is very similar to mine and I use L'Oreal Paris Magic Perfecting Base and it works great for me. You don't need a lot, it gives your face an all over matte feel and look and preps your skin to hold onto the foundation as long as possible. There are other brands out there that people like, so browse around the site for primer threads if you want to get ideas of other kinds.
Because I like the L'Oreal Paris brand for my primer, I also use their new Magic Smooth Souffle for a foundation. I like it because it is really light on my face, doesn't slide off, and makes my face look even. There are others who don't like it at all, especially if they have dry skin or spots. Other great drug store brands of foundation that I've used and had good results with are Almay's TLC (Truly Lasting Color) liquid makeup and L'Oreal True Match foundation. Although the True Match foundation comes in more shades, Almay's has a REALLY long stay time.
I also suggest, if you go with a liquid foundation, that you apply it with a good foundation brush. You don't have to pay a ton for a good one. Drug stores have decent brands at reasonable prices. Make sure it is soft, flat, and has a rounded bristle top. If you go with a mousse foundation, using your fingertips is best.
Don't forget, no matter what kind of foundation you use, you'll want to set it with a powder. That's the key to not having to touch up during the day. If you have mineral foundations left, you can lightly dust one over your foundation with a brush. Or you may want to go with a white, transparent powder which is what I use. I love Make Up For Ever's HD Microfinish Powder, but many people say it is steep in price. An online mineral company called LA Minerals makes something similar (untinted veil) for half the price.
If you go to LorealParisUSA 's website, they have printable coupons for many of their products right now. LA Minerals always has a buy 5 get 5 free sample offer so you could try blushes and eyeshadows too.
Don't want to bog you down with tons of info to process, but hope this helps. Try to buy whatever you decide on at a store that will take it back if you don't like it. Walmart and CVS is pretty good about returns. I've heard Rite Aid is too. If you decide to try more high end items, like ones you'd get at Macy's, they almost always take them back if you don't like them.
Good luck, feel free to ask anything else!!!