You mentioned in another comment here that you're eating 2.5g per kg of bodyweight, nearly every recommendation I see is between 1.4-2g/kg. Be careful with too much protein, one of my gym buddies put himself into hospital with serious kidney issues from going overboard. I'd assumed you were about 100kg lean eating that much protein.

If you don't want to eat vegan food, the only excuse you need is "I'd rather eat meat 6 times per day". The vast majority of western people could eat bodybuilder vegan diets if they needed to. If it is something you're interested in then there is a TON of vegan bodybuilders. Google Nimai Delgado or Torre Washington, for example.