When Dean said “I’m proud of us”

It was his last words to Sam

To show him that even after these fights, even after everything, he was proud of them

That he still loved him and that all that “we’re not brother” thing was just lies

That even though they were so ashamed of themselves, they should be proud

But also because it is important for Dean to say that

Because John was never proud of them

And it marked Dean so much and forever

And he wants to avoid this to Sam