Please I do understand the context but not sure about the form of the boolted words

senden başkası benim için bir rüyaydı

thanks a lot in advance

rüyaydı : rüya + idi  : rüya+y+dı : was a dream

The one except you was a dream for me.

I think he used the word here as it was impossible for him to think that he loves someone except you.

my try at explaining the grammar

/dan başka = other than

senden başka = other than you

senden başkası = see AlphaF´s post below

rüya + idi

(old imek with past tense, = idi, which becomes (y)di after vowels)

bir rüyaydı = it was a dream

benim için bir rüyaydı = it was a dream for me

Dear Henry, thanks a lot for your clear explanation! I do appreciate this so much.

Thanks for your corrections AlphaF

I should have checked a bit further before posting.

I read someone´s translation of 

senden başkası hayatıma giremez. 

as 

Nobody can come into my life except you

and made a wrong assumption based on this 

Thanks for your corrections AlphaF

No problem Henry, a small mistake..