If you can't make the history work, if things feel off, if the timeline you envisioned just isn't working out, quit trying to make it work and rewrite it already. If it isn't working right now, it isn't going to start working five chapters from now. And I should know. I found this out the hard way.
Writing, Again
Rewrites are really the worst. No freelance writer wants to rewrite something they already wrote, and no author ever wants to go back and change a story that's already down on paper. But sometimes, what you've written just isn't working with the rest of what you still need to write. Stories can be tricky like that. And before they trick you into writing 100 pages too many, go back and rewrite.