Calm down. So let's recap:
-couple of days ago, you had a dream. A cat told you that you'd been chosen.
-last night, you felt like you were on fire (awake, I presume), so you ran outside, where it was raining.
-A peach-coloured tabby cat appears and introduces herself to you as Feather. She says that you are Fire.
-She says you two are one and the same.
-You're a cat from another dimension (by dimension, I assume you mean something along the lines of "plane of existence" rather than the mathematical concept of dimensions, which is much different)
-You are one of six; you must find the others.
-Your eye-colour changed, from brown to blue.
-You understand cats now
-You're 10x better, and less affected by temperature now.
-And now you regularly have visions, as well as see and sense spirits.
-You think your friend is another of the five.
Ok. Well, it's quite likely that its all just a dream. Stop freaking out; you'll faint less, and be able to think more clearly. By the sounds of it, you've been reading too much fiction, and have a very active imagination.
Now, of course, drastic, sudden eye-colour change is uncommon, so that's a bit weird. As for your visions of the future, mind sharing them with us?
Finally, I don't want to be a killjoy or anything, but assuming that the Six (five+you, of course) were scattered evenly across the world, the probability that your friend is another of the Six is extremely low (approx. 5/6,819,800,000; your friend is more likely to be struck by lightning 9000 times than to be 1 in the remaining five in the world)
I would suggest just letting it run its course, and maybe it'll stop, or maybe it'll prove to be real, in which case, I'd be jealous for not being chosen.
If it gets worse, and it really starts interfering with life, go see a psychiatrist.