[He had time to think about it. Agonize about it, even, because for a long time it was all he could think about.]

I was close to breaking through. You said so yourself. The fight itself could've done it.

I couldn't...maybe then at least...

[He's trying to say that he wouldn't have been able to defeat them, probably--he hasn't been able to for all this time, after all, but maybe they both would have survived it. The chances would be better with two of them, they always would be. Wouldn't they?]