Here's the sentence I'm trying to express in Japanese. "I have changed my life, I've become a cheerful person, all because of him!"
And this is how I would translate it. 僕の人生が変わったのや、明るい人になったのは、全部彼のおかげなんだ！
Am I using the right particles? My intuition says that the sentence is wrong.
「[僕]{ぼく}の[人生]{じんせい}が[変]{か}わったのや、[明]{あか}るい[人]{ひと}になったのは、[全部彼]{ぜんぶかれ}のおかげなんだ！」
is grammatical and even sounds fairly natural.
The only part that does not quite sound natural is 「明るい人」. We would rarely use 「人」 that way to refer to oneself, but again, it is still all grammatical. You could say 「明るくなった」.
Am I using the right particles?
Yes, you are. I would never call anything natural here when there is a particle mistake.
The third-person pronoun 「彼」 is not something we native speakers use often, but I certainly could not say it is wrong to use it.
