Unfortunately your doctor didn't understand how Botox works. Botox can not be adjusted as he did because Botox is fundamentally treating muscle movement; it only indirectly treats wrinkles. If your muscles in your forward moved symmetrically before your treatment, you have to treat them symmetrically, it doesn't matter what the wrinkles look like. So by putting more on the right side, it is now weaker than the left and you are thus asymmetric.
Furthermore, he used too much on the dropped side. Ideally after Botox in the forehead both sides still move some, and the movement is symmetric without any drop of the eyebrow. Some people do prefer no movement, and that is fine as long as your eyebrows are high at rest. If your eyebrows are low at rest, too much Botox will force them to stay low all the time.
The only correction that can be done in a situation like this is add more Botox to the left side so it matches the right. Of course this will make both eyebrows low, but I think that is better than being crooked. In a few months it will all wear off and you can consider having a proper treatment.