Am I the only one who suffers from this?
Sometimes I'll have an idea I'm excited about, but when I start creating the board my muse and motivation plummets. My excitement and determination for the plot and board to succeed is usually high but I can't seem to make it work.
It's completely frustrating because of the hundreds ideas I have in my head currently.

If someone else suffers from this, how do you combat it?

Omg...I hate it when that happens!

Normally I try and make a playlist of songs that will help my creativity if I start to wane. If I start loosing interest in the plot (i.e. - my muse throws himself off a cliff >.>) I listen to the playlist over and over again.

Sometimes though it's not wise to rush the creativity back, if there's a reason for the loss of creativity you should try and find it, like going back through the plot with a beta or something and maybe pick out things that need to be polished and fixed. My site beta helps me with that kinda stuff all the time, especially if I'm VERY excited about a certain idea. We sit down and talk it through, and toss ideas back and forth, a lot of times that's enough to bring back the desire!

I hope that helps!! :)

This problem happens to me quite a bit. The only way I personally find a way to combat it is to find like-minded people who'll help me to build the board up to original expectations and make things work properly.

That's actually happening to me right now. I'm working on an RPG and I'm in the final stages of creating it and I just don't want to work on it anymore. At all. Maybe if I found that staff member I need it would help me? I also plan on looking up stories related to my plot and listening to music.

I gotta be honest. If you a) require a muse to do it and b) lost drive before you finished creating the game, what reason is there for me or anyone else out there to believe that it will last? Who is to say you won't turn around and lose the 'muse' for it once it has been launched? Games are not self-sustaining until a few years in. You will be relied upon to put in constant hard-graft to make it last.

My advice is stop. Take a step back and do something you are able to do right now, without the inspiration. Creating a board that rides on the back of your muse is a recipe for disaster. It will fail. You need to cook this for longer if you want it to stand a chance at surviving the first 12 months. You need to dip in and out of it, let the ideas form as they will and you need to be confident that you can run this without a muse. Otherwise, what hope is there when the muse runs out on you again?