As a fellow guy-making-an-RPG, I wish you the best :D I don’t use RPGMaker either so I can’t help with specific advice on that tho.
Jeroen is right that RPGs are a really big undertaking, and that you can’t maintain motivation on such a project forever. But don’t let that discourage you either, take breaks when you start to feel burnt-out and jump back in with a fresh perspective.
It can also help to talk about what you’re working on with friends or other devs, from my experience there’s nothing more motivating that seeing what someone I know has been up to and wanting to share new stuff with them.