This happened to me on 13 of August.
Until November i was staying away from the sun.
In November i was On holidays in bali and i was putting a lot of sunscreen on my legs when i was at the beach.
When i returned from bali my spots were much better than before you could see them but slightly.
Now i went 5 times to the beach and my spots Are almost gone.
You have to start slowly first days 3-4 minutes in the sun to check how your body will react.
At the moment no one can see the spots. You have to put a lot of body lotion to hydrate your legs all the day.
I visited many doctors and they told me that they might take years to disappear. One doctor suggested me to go in the sun for few minutes per day and it worked for me.
They also suggested me to do phototherapy but it was to expensive so i tried the sun and it worked.
Donāt forget to put cream to hydrate your skin and off course sunblock.
My legs were horrible and my psychology was really bad. I can understand how you feel.
It will go away dont worry!