How do I handle a job whose travel and hours are ruining my personal life?

When the hours and the travel start eating your personal life, that is not a small complaint to push aside. The job will always ask for more. It is built to. The relationships and the rest it costs you will not send a bill until later, and by then the damage is done. So it is wise that you are noticing now. You may not be able to change the whole job overnight, but you have more control than the pace lets you believe. Protect a few things that are non-negotiable: a night that is yours, a call home you never skip, a boundary you actually hold. The work will fill every inch you give it. Your job is to stop giving it the inches that matter most. As for advising on companies you have never run, that quiet doubt is not a flaw, it is honesty. Use it. Stay humble, ask more than you tell, and never mistake the confident slides for the truth. The best advisors know the limits of their own view. Let that keep you grounded while you get your life back in balance.