Wet iPhone - now nearly black screen

Hi Everyone,

I hope you can help me. Unfortunatly I've sent my iPhone swimming yesterda. After I pulled it out I towled it down and let it dry. Afterwards, it appeared to be working fine with a bit of flickering. A few hours later the screen turned nearly all black. It looks like the phone is working just the screen is only 3-5% bright. Very hard to see something. Furthermore when someone calls the phone only vibrates but doesnt ring. Is there anything is can do? Do you have any suggestions?

Thanks in advance.