Your desires are answered by the universe in the moment that you had them so time is irrelevant as to whether they get created or not...they already exist regardless of what you do after you've had them.

In order to proceed with this answer, I think it's important to realize what manifesting really is - it is personal perception.

You can decide at any time to be willing to give meaning to a particular moment in your life and say that a manifestation has occurred or not, but it's just you giving meaning to a perception. There is nothing absolute or fixed about a manifestation.

Your life will "manifest" itself perfectly on auto-pilot if you let it - your role in the creation process really ends at the point at which your deciphering of the contrast of your life causes a launching of a new desire within you. The rest of your involvement is whether you want that eventual perception of what the launching of the desire has created.

So you can have an unlimited number of desires coming into manifestation simultaneously regardless of the attention you give them because you launched those desires incrementally. See: I want to manifest lots of desires. Should I concentrate on only one at a time, or more than one? It doesn't matter how much your attention flits from subject to subject, it will still happen as a natural life process.

So what I'm guessing you are really talking about with your feeling about lack of direction and its accompanying frustration is really just about not having that feeling of being a creator of your life ("having your hands in the clay") which is the concept I mentioned in Is meditating and visualizing indicating that I am not letting it go and I am not trusting? It's basically a lack of focused involvement (in that process that will happen anyway).

But the other point I'd like to make is that, because of the principle of the Next Logical Step, you are always going to be bored and lose interest in your desire to some extent before you are aligned enough with it for it to be perceivable (i.e. manifest) in your physical reality. So you will always find your desires have "expired" (in comparison to the initial thought of them) by the time the physical manifestation comes.

For that reason, the real thrill of living must come from the initial launching of the desire and the accompanying envisionment of it because the physical manifestations are always going to be boring by comparison. It's that "The joy is in the journey" business that is so eloquently expressed in Ithaca.

If any of these ideas are new to you then there might be some head-spinning concepts in this answer, so I hope I've explained them clearly enough.