What does this mean?

I really liked a manga but I found a sentence that is not translated and I don't know enough Japanese to read it. The message was extracted from a letter.
This is the message:

七星たんへ [To Naho-tan]
ゼッタイ　鬼碑忌　先生　を。。。
見つけてね
大好きだよ　　私がもし死ん。。。
きをおとさないで。。。
れいのうたんてい。。。
ずっといっ。。。

ゼッタイ Don't fail
見つけて to find
鬼碑忌先生 Kibiki-sensei
大好きだよ I love you so much
私がもし死ん If I di... (incomplete)
きをおとさないで don't be discouraged
れいのうたんてい psychic detective
ずっといっ I want to do it always with y... (incomplete)

By the way, I had played the first game "corpse party" for PC-9801 by Dante98.
I remember that pictures were limited and very poor, but the writer showed his genius clearly.

Oh! "Corpse party" lines seems saying last words.

ゼッタイ　鬼碑忌　先生　を。。。
見つけてね
teacher Kibiki...
Never fail to find...

大好きだよ　　私がもし死ん(でも/だとしても)。。。
きをおとさないで[気を落とさないで]。
I love you, if I dided...
Don't be lose your heart.

れいのうたんてい[霊能探偵](の貴女[anata:you]と)。。。
Ghost paranormalist detec(tive)[Naho]...
ずっと いっ(しょ[一緒]だからね/-だよ)。。。
and me with for...(ever)

Thank you!
The manga is "Corpse Party: Book of Shadows" and that chapter is called "Purgatory" (is the chapter 3.5) but it's not translated yet :(