That's exactly the one you should pursue.
Because that's probably the important one. The one God is speaking to you. Calling you
Maybe that's why it seems so large. Because it's a God sized dream.
That fear? Maybe that's a sign you're on the right path. Fear is the enemy. Trying to make us doubt ourselves. To discourage us. To keep us from following God's plan for us.
It seems impossible. But with God all things are possible.
Push past the fear. Trust the One who first imagined the dream and passed it to you. The One who can make it happen. Step out in faith and obedience. Pursue the dream.