To be really honest with you, it is inhumane to force the cat to be something it is not. And it is inhumane to force a wild creature to do something it doesn't want to. It is a wild animal even though it is a cat. I can't answer your question fully without knowing more. How old is it? Is it a kitten? Or is it a grown cat? What are you trying to do with it? How and where did you find it? Can you touch it? You say you have had it for five months. What has the cat been doing the whole time? Where has it been going to the bathroom for the whole five months.
If it enjoys people and likes you and comes up to you without ever hiding or running away, you have something going.
If it hides everytime it sees someone or hears someone, the cat is scared and stressed out. This is not good for the cat and it is living in fear. At this point since you have had it for five months you have to decide. It is inhumane for a feral cat to be living in fear.
I trap, neuter, and return (TNR) feral cats in my city. I do not even think about trying to tame a feral cat, simply because it doesn't want to be. It causes extreme stress for the cat which isn't good for its health. That could also be the reason why it isn't using the litter box because it is scared to death and stressed out. When domestic cats are stressed out they do not go to the bathroom in the litter box.
It is not inhume to have a cat fixed. It prevents cat overpopulation. It is not inhumane to have a vet notch the cat's ear if they are feral. It is a simple procedure where they take the tip of the ear off. THIS CAN SAVE IT'S LIFE. It lets peole know it is fixed. Notching the ear is a lot more humane than getting retrapped and having another surgery. If anyone says it is inhumane they obviously don't do this or understand the whole situation. Allley cat allies is a good place for feral cat information or you can read my hubs.
I cant answer your question throughly till I get more information.