Maybe grass doesn’t grow on your minecraft anymore because you shaved it too much? I’d say to see a dermatologist if the problem persists. As for making it bigger, you get the minecraft you’re born with. I see you mentioned changing the size, but you shouldn’t worry too much about that. If the lava won’t flow, you might want to look into cutting back on the soda and carbonated beverages and increasing your water intake. Good luck.