One immediate idea would be if you could potentially freelance for a few different companies that maybe weren't busy enough to justify hiring someone full-time to do what you do. I don't know enough about what you actually do to provide concrete advice on this, but I would expect there are smaller companies that don't do the same level of international freight, and those companies probably would rather hire a freelancer / contractor to work n hours per week instead of having you on full time.
Contractors are typically paid at a premium, so if you could find a handful of companies to pay you maybe $30/hr for what you're doing, you could work half as much and make quite a bit more than what you're making now. Again, the wildcard here is the value of your benefits package, and what it would cost for you to buy benefits in the open market.