Chucky is right..(God, I hate typing those words....
If your kidneys are healthy, protein does not harm you in excess, but it will be wasted if you go over 50 grams per meal in any given 120 minute period. You need approximately two hours to fully digest most protein, although good egg albumen and whey isolates will stay in your bloodstream and be activley synthesized for slightly longer, helping you avoid slipping too far into ketosis (edging it is good - too much is not so good).
And your calculation is high ONLY if you're not lifting with high intensity for at least an hour a day. Then, it's a waste. Your body will put it to good use if you're putting your body to work - hard work. And hard work means you're pushing up your numbers and not just doing the same thing this month that you were last month. *ehnnnnn* If you're just the average gym rat, then it's all getting (literally) pissed away and you should save your money.
If you are doing serious lifting - what is too easily referred to as HIIT- and properly, then you are going to see real gains in lean mass. But the minute you stop training like that, but still eat as if you were - you'll see a backslide in the direction you don't want to go.
What you can think about doing is buying a good quality casein (cottage cheese is actually one of the best pure forms in solid food, and there are fat-free and low/no lactose brands, too) and having 30 to 40 grams before bed. It's a slower digesting protein that will keep properly nourished overnight, and help you slip in a seventh or eighth 'meal' so that you divide your 300 grams into 35 to 45 gram portions over the course of the day, which should be pretty easy to manage.
But the real key to kick your ass in gear is in the gym before it's in your diet. You can't eat for what you're not training for....(good luck parsing that sentence...)