Focus on incremental improvement. You don't have to rewrite the entire system to improve the architecture. As with many things, moderation is the key: if there's something blocking the actual work you need to get done, give yourself an hour or two to refactor it enough to do the thing, then go do the thing. It doesn't always have to be 1:1, but if you tie a refactor to the actual thing you need to get done (and you keep it very small and self-contained), then you'll always at least be doing something.