Iphone 6 randomly typing and clicking on its own?

I dropped my iphone 6 in the toilet last year and i put it in a bag of rice and it worked well afterwards. And this year i dropped my phone on the ground and it shattered the screen but i can still click and type well. Then i had the screen and lcd repaired. But after a few weeks, it started typing and clicking on its own. What is damaged? Is it the lcd? Or the motherboard? Or what?

Who repaired it? Obviously it wasn't done right, you should have taken it to an apple store, now you will end up paying to get it repaired twice, where Apple would have stood by their work and made it right.