my iphone wont turn on.it only stays on the loading screen.

well! last night i resetted my iphones setting because my cousin wanted to purchase it.
after the process was done, my iphone apparently died while i was sleeping. so all day today ive been trying to turn it on for my cousin. it only stays on the loading screen.
i can still reset it by holding down the 2 buttons but it still wont turn on....Please help me!! i cant afford another phone..

yea i have.ive done everything.it still wont get past the loading screen. i dont get it!