5. soda says to his brothers, “if we don’t have each other, we don’t have anything. if you don’t have anything, you end up like dallas…and i don’t mean dead, either. i mean like he was before. and that’s worse than dead.” what does he mean?

Dallas was in an awful position before he was killed and he was living a bad life, so he's saying they should stay close to keep a good life together

When Soda says "And that's worse than dead", he means that not having anything or anybody to be there for you is worse than being dead. Dallas didn't have anyone except for the other Greasers before he died and Soda is saying that if they were to lose each other, they'd end up alone and like Dallas, which he thinks is worse than being dead.

Hope this helped! :)

Conclusion if that's an answer.