Q: and it sounds really dull. in guitar you have up and down strumming but in piano that isn't an option so i have empty space in between chords. i gotta fill that space. How do i put together melody and chords and come up with a good sounding accompaniment.
A: just keep doing what you are doing. you will be amazed at how many interesting things automatically come to you if you just keep going the boring way. certain small additions will become irresistible, one by one