Romaji to English

I need help with translating a small piece of lyrics from "hold me tight" by asian kung-fu generation.

kimi ga inaku natte kara to iumono
boku wa koko ni tatazumi
omoide o kono mune ni
nanika o motomete ikite iru

Ah, kimi o omoi utaundayo
Ah, kimi o omotteiru

Im sure its probably similar to the rest of the song, but I really want to have it translated properly.

Since you've gone
I've been standing here
With your memories in my heart
And live looking for something

Ah I sing for you thinking of you
Ah I'm thinking of you


Simple and good lyrics. And this is rmy rough translate.