Moved the truck to get fuel, now running out of hours

The answer you don't want to hear:

You're screwed, and if the office tries to "fix it" for you by editing the logs, they are committing an act of falsification.

The answer you want to hear:

Don't worry about it. Mistakes happen just don't do it again. Learning from mistakes is a big part of all of this. Do what you can within the confines of the law and get the job done from here.

The answer you shouldn't hear:

Most fueling places don't time stamp your receipt (but if it's a company card, there will be a paper trail the DOT could chase if they wanted to), so you could have "made it work" with personal conveyance just so long as you put in time for fueling at the start of your day. But had you got into an accident and they ended up tracing the log, you'd be screwed too. Plan better next time.