My iPhone got wet and the sound keeps cutting out?

Basically I dropped my iPhone in the bath with my headphones plugged in. They were over head headphones so they didn't go in because they are quite heavy. I yanked the cable straight away and the phone came straight out of the water. I unplugged the headphones and had to leave my phone on the floor (still on) for about 5 mins so I could dry off and stuff. Then I turned off my phone and put it on my window ledge where the sun was to help dry it off as my radiator wasn't on.
When I came back, my phone was switched on, so I switched it back off, and it turned on again. I searched this and this is apparently a good sign to show it hasn't been truly damaged.
But, when I listen to music (e.g. YouTube) the music cuts out for a bit. When this happens the music volume slider disappears and the video is still rolling.

What should I do?

Dry the iPhone and change its batteries wait for a week and if it keeps happening then take it to a technician to repair it before it gets out of hand

That happened to me. It's almost like your phone thinks its plugged into a speaker. It can take a few weeks for everything to be completely dry inside the phone. Mine eventually worked, but then my microphone started going in and out.

The same thing is happening to me. It's driving me mad