There are times, in your relationship with God, you have to take a leap of faith.
God is faithful, He always keeps his promises. So when He says I am going do something, He will do it, no matter how much time it takes.
In the meantime, you might have two enemies: doubt and desperation.
When you see that time is passing by and nothing is happening, this is when you start to doubt, when you doubt, you start having a negative mind set, and then you start losing faith in the promise.
The second thing is desperation. Do not become desperate. Things might not happen when you expected it to but God has an amazing plan for your life and you should trust Him no matter what.
God might want to test your faith, so you must at all time believe He can. Take a giant leap of feat in your life. Let God do it His own way.
God is the God of Possible. In Him, there is no disappointment.