best way to fix that is to get a stand that is built for a 10 gallon aquarium, you have to remember a 10 gallon aquarium weighs a little over 100 lbs when full, and most nightstands and dressers will not withstand that extra weight for long, and they are also not perfectly level on the top for the most part.
now you said the tank itself was wobbly on the stand. that could be bad because it will cause uneven pressure on the corners and cause it to bend and twist. which will eventually cause the seams to bust (could be days, weeks, months, or years no way to really tell).
so i would just recommend finding i nice level and sturdy place to put it on, or buy a stand built for aquariums.
i will add that if the stand itself was leaning and the aquarium was laid nice and flat on top of the nightstand, then would not be such a huge problem. My 38 gallon is about 3/16 of an inch higher on the left then the right, but it is the stand itself that leans, and not the aquarium because it is an a stand made for aquariums