Water might have got inside my Samsung S5. Can I get some advice?

Water might have got inside my Samsung S5. Can I get some advice?
Added (1). ?
Added (2). I had my phone in my bag which got wet at work. The phone kept working for 1-2 hours then it kept restarting only showing a black screen with its name and powered by android and then it shows thin horizontal white lines. I got the battery out. The second time I put it back it came back to normal. I even called someone. This process happened twice.
Added (3). The usb cover is missing. It fell a long time ago. Anyway, the phone isn't dead, but not really alive either. Now it's sitting in rice. I know it might be too late but since at first it worked… I din't know. I am still hoping the water isn't the actual problem.

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