Help with vitamin D overdose?

i was tested with a low vitamin d .so my doctor prescribed me with supplements.although my symptoms were not severe i had feelings of some lethargy for a few months an not upto my energetic self so i went with the test.but i got overenthusiastic with the medications.the doctor prscribed me a sachet of 60000 IU every week.i took it twice a week,added a couple of cod liver oil capsules every day and had around 1-2 hours of sun exposure every day.so initially i showed good progress and started feeling very energetic in 10 days or so.but since last 20 days i am again feeling very lethargic,with muscle cramps,muscle twitching-i think with overdose of vitamin d.so whats should be my treatment.is this comdition treatable?