We recently got a new Maine Coon kitten (both kittens are in my post history in case you're curious) to add to our family.

We got him at 6 months and was introduced into our home without going through any introduction methods or anything (wasn't really aware of them, it was our first time having more than 1 pet in the same space) and they got along fine at the start.

After he was old enough, we neutered him, much like we did with our senior, to avoid spraying and territorial aggression, and other than the new kitten being a food hog and going for our seniors food, things went well, he was super energetic and played a lot and things went well.

However, now that he's around 10 months old, and he's twice the size of our senior, he's started getting very pushy and territorial, and started attacking my poor senior who's less than half his size and weight, and who's got health issues, so he can't really fight back.

He pins him to the ground, runs him out of some of the rooms in the house, like the living room, tries to push him away from his food and eat it himself, and our senior seems to have retreated to one or two rooms to avoid him and is so stressed that his fur is falling out. I feel horrible because it feels like he's afraid in his own home.

I'm at a loss and don't know what to do since I've never had this issue and never been in this situation before, and i don't know how to discipline the kitten because he seems to not listen at all, and it's very frustrating, which doesn't help since we get desperate and the cat senses that and gets more agitated...

Any tips are welcome, i really don't want my little guys to fight, or lead my already debilitated senior to an early grave from stress :/