Cracked Screen and Water Damaged iPhone! Help!

So I had previously cracked my screen a month ago and now I accidentally dropped it in the toilet. I immediately took it out and dried it and it was still working for a minute but then the screen started to show lines. I then turned it off and then put it into rice. Two hours later I turned it back on but all i had was a white screen and I tried turning it back off but it wouldnt so i left it on and the battery died. That was probably the dumbest thing i ever did but i wanted to see if it still worked. It has been 24 hrs since its been in rice and i tried charging it and it wont work.

I've seen where people have bought a new battery for their iphone and it starts working but I dont know if I should even try doing that because my screen was crack in the first place. Can someone please help me...thanks!