I think the empath fatigue we get from our energy exchanges, are just part of the deal for a developing empath. Perhaps it's a lesson to be learned to better control our energy exchange skills to be used sparingly and in the right circumstances. As opposed to how the majority of empaths exist, myself included, who don't yet have full control. And we accidentally exhaust ourselves with our empath radar being up and working on everyone.
This is probably a terrible analogy, but I can't think of a better one. I live in rattlesnake country so this came to mind as a way to explain empath fatigue. And the young youth snakes put themselves in danger because they release all of their venom in their first encounter. So if they are out hunting for a mouse, for example, a young snake will through inexperience use enough venom to kill 10 mice in a one mouse hunting attack. They then get fatigued, and will need many hours or even days to rebuild their venom stores. That leaves the young snake unable to defend against predator attacks in the meantime, and also limits their options to continue hunting for food. On the other hand, an adult rattlesnake knows how to use its venom sparingly. And knows to be picky and very selective on when to hunt, when to fight, with an emphasis on rationing its venom.
I think we empaths are very often like a young rattler in how we use our gift. Most of us, myself included, don't know how to ration our gift and be selective with who we use it on. We might go out to dinner at a crowded restaurant with our empath radar on full and pick up all of the energy in the restaurant thereby allowing an energy exchange with many random people. And that exhausts us. We can also while picking up on all that energy pick up and become like the low energy in the room (nervous energy, sad, angry etc...).
I was recently reading an article by a pretty famous psychic who is very skilled at putting a protective white light bubble around her to protect the empath part of her. That way when she walks into a busy restaurant or public place, she isn't allowing an energy exchange with anyone. She only puts her empath skills to work selectively when she decides someone needs her help. This makes her more powerful and effective on people who she helps, when she chooses to help them. And she doesn't spend her day struggling with any exhaustion from overuse of her resources. And like the adult snake in my above example, she is being highly efficient by being selective.
In a round about way to come full circle on the original question in this post, I think we can manage the fatigue and emotional effects with protection crystals, salt baths, rest etc... But the real relief and much more emotionally stable existence will come once we master our gift and learn how to go through life without having our empath radar on high ready to interact with everyone we meet.