I think you've done a great job to shed 50 pounds!
I don't believe in this high-protein diet, especially not for the average person (maybe bulgaria´n olympic weight lifters on roids need that much!).
I'd suggest that you concentrate on eating healthy vegan, with not too much sugar and fat in it, and lots of fruits and veggies.
By starting to exercise, you should increase your metabolism so that you burn more calories. If you don't overeat, you'll be losing fat.
Concentrate on healthy food, don't overeat and work out. Try not to make a diet for a weight loss in a short period, but to maintain your weight or lose slowly, in a healthy way.
Counting calories or calculating protein/carbs/fat ratio sucks - it takes away the joy of eating! As you don't seem to have a serious issue with eating or overweight, you shouldn't need that.
And search the forum, there are lots of threads that treat similar subjects, you'll find more info i'm sure.
Feel free to ask anytime if you have questions or think the answers are insufficient
love and peace,
Two new posts while i was writing!
There don't have to be maths! Weight watchers is good to shed pounds, but i think for vegans there are better alternatives, especially when you've already lost the main part of your body fat. Life should be fun, and your diet should come naturally. Don't calculate! You don't have to calculate if you eat veggies instead of ice cream!
And once in a while vegan ice cream is not that bad...