I hate to break it to you 2D, but nobody will help you with this unless you show them a game that's at least partially complete. That's just how it works.
Sure, you might find some people willing to try... but it's very rare. And those people will have just as much of a clue as you do about finishing the game, and in less than a month they'll all ditch on you because it's too hard. It happens every time... yes, every time.
Anyone who is serious enough and good enough to actually help you finish the game will need to see proof that you've put some hard work into it. But even then if you're not offering money the chances can be pretty slim.
Here's your best and most likely option: Plan to spend the next two years making just that one game by yourself. Work on nothing else. Concentrate on that project 100%. If you're serious about the game, and the game is worth the time, then this shouldn't be a problem.