I don't want to cook for my bf even though he's temporarily immobile
Don't you think you should help your boyfriend out?
I want to be a good girlfriend but I'm too lazy to cook.
It is good that you want to be a good girlfriend but you will have to do more to help him. He cannot help himself and as his partner you have to help him out now.
What should I cook for him then?
You can look for simple recipes that won't take long. That way, you don't have to cook for too long and he can still eat.