What can I do to at least avoid the gains and backtracking my progress while I am very much away from my usual routine?
Without knowing your current level of fitness, it's honestly difficult to say.
Since you mention equipment/lifting in order to maintain your current fitness, it's perhaps possible that you're more bulk than lean (or at least, maybe that's what you're aiming towards).
In any case though, if you don't have access to equipment then I think the most you can do is a collection of no equipment plyometric exercises.
That link contains exercises that I myself (as an avid runner and now casual weight lifter) perform in order to maintain decent strength (relative to my body weight) and without needing equipment. They can be done anywhere and at any time and the level of intensity only depends on the rep count and/or speed at which you perform them.
At the very least this will keep your mindset focused towards physical health (beyond a clean diet) and allow for you to maintain some kind of workout routine until you're able to return to your normal schedule.