Hi there Nick...
I guess the way you get motivated differs from one person to another. In my case, I would love to see something visual on the screen, so I try to at least draw something on the screen at the end of every session to feel there is a progress.
Another way is to reward yourself. I split the project into a number of sessions and a goal needs to be achieved by the end of each session. Every time I achieve a goal I would mark that and see the total process. After that I would drink coffee, have a walk, take a rest or make some kind of change. Again this works for me, and don't know about others.
Just try to find a way to reward yourself and integrate it to your routine.
yours sincerely
mkaatr