When i'm angry, my dog becomes clingy to me, sometimes it makes my anger subside, sometimes i just shove my dog, especially if he's the cause of my anger...
When I'm depressed he just lies down beside me, automatically i'll pet him
When I'm happy he'll just look at me contentedly and sometimes i'll play with him
Your dog could be, but as I said before, you are really the only one who decides if he is your familiar or if he is just really close to you.
I would slow things down a bit. You should make a connection with your kitten before you try to make it your familiar. Remember to play and take care of your kitten a lot and in time the bond between you too will be very strong, and slowly it will become your familar. Just don't try to force things.
I think my dog is my familiar. Whenever I'm sad or in pain he licks my palm and I automatically either feel happy or not in pain anymore. Whenever I decide to cast a spell, which I haven't done in a while he lies down in the circle next to me and is just completely calm.
also, my dog often barks in a certain part of my room(which i rarely use now because i feel something there) and when i'm in trouble he just looks at me with his big eyes, like he's saying he's cheering for me