Eat at 3400 for about two weeks, make sure you're actually tracking your calories; weighing and measuring everything. Let your body adjust to maintenance and the lifting program. You may even see weight loss eating at maintenance since you are a newbie. From there, taper your calories down SLOWLY. Losing 50 lbs is most likely gonna take you a good 5+ months, just stick with it and don't try to rush. Any whole food protein of your choice is optimal. If you absolutely have to, you can use whey protein. The brand for the most part doesn't matter. Try to find something with a low carb to protein ratio. And yes, you are essentially depriving your body of the nutrients it needs. I won't use the word "starving", you're not Kenyan.