Congratulations! I would suggest only adding 5-10g of carbs per week, not jumping to 50g immediately. As you slowly add carbs, you can see where you are when your weight loss stops and you're out of ketosis. That way you can adjust your carb intake more accurately. You may end up at 50g, but that may be too much so don't risk stalling and winding up discouraged. At least that's what I'd do anyway... Good luck finding that magic number that's right for you.
God Bless,
Amy-Lynne