Restylane Effects Gone 2 Weeks After the Procedure. What Happened?

It sounds like one of two things are going on:

It could be that the initial satisfaction you had was related to swelling and now that this has subsided, there may not be enough product to fill the area in question.
It could also be that the product was injected incorrectly which will cause premature degrading.

Either way, 2 weeks is much too short a time for the product results to disappear. We suggest as a starting point to go back to your injector for a checkup to further explore what's going on. If that does not work out well for you, get a second opinion with another injector. Good luck.

Generally the nasolabial folds are deep structures that benefit from significant volume.
It was likely injected on the deeper side which can hide some of the fullness but if you inject it too superficially it may be too visible.
One syringe is probably not enough for you and you may likely require two or three syringes. Obviously that presents a financial burden for you.
The alternatives are to undergo other fillers such as Radiesse which pack more product into each syringe or to contemplate autologous fat injections which cost more upfront but may provide you with a longer term result.