Help! Terrible makeup?

ok, so I've tried various foundations and NOTHING works well for me.

I have combination skin and I've tried moisturising with an oil based moisturiser + an oil based foundation, and I've tried moisturising with a water based moisturiser + water based foundation….but always at the end of the day my face feels tight and my makeup is half gone and it looks 'dotty', as if it has clumped up in some areas.

I apply with a sponge, make sure everything is blended…I've even tried clinique's moisture surge spray (if im wearing water based makeup), but still it gets blotchy/clumpy after about 1 hour.

I HAVE to wear makeup because I have a bad case of hyper pigmentation :( . I believe I am really beautiful, I love the way I look, but my skin doesn't bring out the best of my beauty. I don't know what to do, I'm always hiding my face, and my skin feels terrible and I can't concentrate on my college work…when I get home, I check my makeup in the mirror, and you can see my pigmentation…it looks all grey, and my makeup is all over the place, hard and clumpy (even though its a nice golden colour when I leave the house)
What am I doing wrong? Any suggestions of a foundation for TERRIBLE skin like mines?
I need a high coverage that doesnt cake up or dry up.

Why does makeup look perfect on everyone but me?