Staying motivated... I don't think that's possible. I lose motivation and morale all the time. Often, things seem like they're going nowhere, or so slowly, that they won't be worth my time anymore.
So what do I do? I just post. Thoughts and laziness fight against me, I pull myself to do it, and I do it. Even if I write something shitty, I have nothing to lose. Because at the very least, I progressed the thread somehow. I contributed, and I kept it that one step closer from dying. I don't like to think too far ahead, getting myself all overly excited on parts we might not get to. Instead, I look at things day by day, moment by moment, and think of every post I've made as an achievement in the fight against laziness, and the fight for progression. I make plans for that day or maybe even for the week, but nothing more. This helps keep me going. Focusing on one thing at a time rather than the future and getting all overwhelmed by it.