As long as you want to maintain a male physiology and you have no natural production of testosterone, you will need to keep taking your testosterone for life.
Never reduce your testosterone without supervision from your medical providers.
If you reduce your testosterone while you still have female reproductive organs, your menstrual cycle will usually begin again after reducing your testosterone.
If you needlessly reduce your testosterone, you will also run an increased risk for osteoporosis (brittle bones).
Your testosterone should provide you approximately 250ml every 14-21 days, for life.