What's up with the second half of this year? Is it cursed or something?

My company's workload is already high in terms of variety, time, and complexity compared to other departments. Now, I've been assigned the miscellaneous tasks of someone who's quitting next month... On top of that, I heard another person from a different department is quitting next month, and I'm expecting their workload to be dumped on me too... Seriously, hire more people! Why are you trying to pass off the work of two departing employees to the rest of us and call it a day! The burden is falling on the same person every time! You know this!!!! Just because I'm a supervisor doesn't mean I can be a superhero who can do anything! I'm already overloaded! Our department already lost one indirect staff member to another department last year, and now we're going to lose another one to a different department in next month's personnel review!! How much of a dead-end position do you think this is? We're working overtime every single day! ...I came home wanting to vent to my family about this, but when I got home, I found someone who had hit-and-run my car waiting for me, and my mood just deflated. (The punchline)