I like to use the old adage. "Garbage in; garbage out." It doesn't really matter what you use as much as what you put into it that counts. I have used all manner of instruments, acoustic and electronic; recording to tape, to sequencer, to digital; and when something doesn't work, it just don't work.
I would recommend getting a MIDI keyboard controller since it allows you a lot of possibilities in sound generations, either with hardware sound or software sound modules. Then take some time to pick out some songs to learn to play by ear. As you learn them, your understanding of common song structure will increase and you may be able to reach your goal much easier. Perhaps picking up a Piano Chord dictionary will add some extra options to how you can play chords to achieve different flavors of the same song. I always keep one around to show me some options.
The equipment is not as important as the understanding you develop in your head. That will make it far easier for you to express yourself in the long run. This has been my experience.
I can't really tell you what kind of music will come out of your head. But whatever it is, it will likely be in your own style, so don't be disappointed if you don't produce something similar to Sheeran's music. But keep working on it and share it with others. You may be the next Pop sound the world is looking for. Best of luck and don't give up!