Congratulations on your first feature complete game. It really is a big accomplishment.

Now, I am hardly an "industry veteran" or any kind of expert, but I've been designing tabletop games for most of my life, and "trying to break into the industry" for about 10 years now, "trying" being the operative word.  I have something like 18 different designs under my belt now, some of them relatively short, and some of them in the hundreds of pages. Most of them, until recently, have been released as "indefinite ashcans," much like your own game. There are a few observations I can offer based on my own, admittedly very specific, experience. I wouldn't exactly call this advice. Just some stuff to keep in mind. 

• People really don't care for ashcans all that much, in general. To you, this game is the most precious and unique thing in the world, and understandably so, but to them, well, it's just black words on a white screen, presented in a layout that looks like it could have been directly exported from a google doc. They are busy, and tired, and struggling, for the most part, and it takes a ton of time to read through, understand, schedule, and play a new tabletop roleplaying game. When they see something that they perceive as "generic" they're usually just going to switch off.
   
• That said, if you format it nicely enough, even without artwork or any fancy bells and whistles, and put it out there, you will likely get the occasional taker - people who at least are interested in checking it out, even if they never play (from the perspective of a player / GM, as opposed to a designer, actually playing a ttrpg, any ttrpg, can sometimes feel like a miracle, depending on one's social situation, schedule, workload, etc.). Most of the time, if and when this happens, they will not tell you about it. You might see a download in your analytics, and that's about it. Every once in a while, someone will say, "hey, I played it, and it was pretty fun," or, "hey, I played it, and it's not for me, but good job making it" or what have you. If you polish it up a bit and put it on here or Drivethru for a few bucks, you'll even make some sales here and there.  Never more than enough for a sandwich, but hey, free sandwich.
• Even if it's NOT a plain text ashcan, there's really very little in the way of guarantees if you don't already have either a marketing budget, the ability to afford the convention circuit, and/or basically the time and energy to be a full time marketing executive and spend full time hours doing market research, gathering leads, drafting press releases, etc. Despite the fact that a lot of my games are released as ashcans, I'm actually a professional and classically trained artist, and a fairly decent one. I only did the "indefinite ashcan" thing because I enjoy designing systems enough that, for a time, I was just excited to move onto and experiment with the next idea as soon as I wrapped up writing on the current one, and art takes a ton of time and energy. However, when I decided to move away from that approach and into fully illustrated, professionally laid out, fancy schmancy, presumably more "marketable" projects, I still had massive amounts of trouble, given the very limited resources that I have, getting anyone to notice or care.
  
  My most recent kickstarter had a goal of 3k and featured all kinds of art and plans for a physical book, etc. The book itself was already more or less finished, at 250 pages, and even the quick-start document is close to 50. The campaign just ended less than a week ago, in failure, of course, not even half way funded. The global economy is in shambles right now, and algorithms are increasingly difficult to swim against, so maybe that's part of it, but basically, it's hard enough to get attention when you have fancy, hand-painted images, bona-fides, and press releases. An ashcan is going to have a pretty tough uphill battle simply grabbing a potential player's attention. 

• It takes weeks, months, and sometimes years for an ashcan game you put out there to get even one comment or review. I wouldn't be too discouraged if there's no traction after only five days. Besides, this is your first game. It's a very impressive achievement, but you've likely got years of hard work ahead of you if you're interested in being a designer, and that's okay. You might be jumping the gun a bit. Since the game is free, I can assume you're not trying to make bank on this (very few people in the industry can make a consistent living, even those with "successful" projects), so there is really nowhere to rush. The core ruleset of your game may be in a finished state, but I can almost guarantee you that it's not nearly as well written as you'll want it to be in a few years' time, just because that's how things tends to go. You can spend another year, easily, on polish across all areas, and presentation, and never run out of things to do.

In short, I really sympathize with the exhaustion and the fear of crickets, so to speak. The silence can be deafening. But it's just kind of how things go. Again, it's your first game. You did it. You accomplished it. It may very well serve as a great foundation for you moving forward, but there is no need to rush. Even with way more marketing resources than you likely have, it's a crap-shoot, and it's better to manage one's expectations. Your life and survival don't hinge on this, so you can just take your time. Pat yourself on the back, give yourself a prize if you can, celebrate, rest. Then do whatever you want to do, and if you want to keep pursuing game design, that basically just means getting right back to work, usually surrounded by the sound of silence.