In the meantime you could try an OTC version, but custom ones made by a specialist with corrections are far superior to store bought ones.
The analogy I like to use is sunglasses vs. prescription glasses.
If you need vision correction and you go outside in bright sunlight, are you going to go to the drugstore and buy a pair of Raybans? You could, and they would make your vision a bit more comfortable in the sunlight. However they wouldn't help you see clearly. That's why you would go to your optometrist and get a pair of prescription sunglasses so you would have comfort as well as good vision.
The same holds true for custom podiatrist prescription orthotics vs OTC or shoe store foot orthotics. If you have foot pain or deformity, podiatrist ordered custom orthotics are far superior and less costly in the long run.