What I am trying to do is to put more energy and more melody into my singing.

I don't worry about loudness, that is what the microphone is for.

There are two ways of performing the notes that you can't reach.

1. Sing them quietly.
2. Talk or even shout them out.

As for trying to sing more melodiously I listen to Oliver McElhone on Youtube and try to put some roundness (for want of a better word) into my tone.

Also I smile when it is appropriate, because it comes out in the performance.

Use the microphone as a tool, varying your distance from it for effect.