Looking for advice. Been working on my startup over a year, its not ready, its blowing up, i will not promote

I am looking for some advice. I have been working on my startup for over a year. Its a business automation tool that is just really fucking complicated to build. On one hand it is incredibly impressive how far its come and what it can do on the other, its not ready and I am starting to feel like I cannot do this on my own. Our business has "busy seasons" that gets heavy use for a couple months out of the year and that point is coming up so I am trying to get feedback and get this thing working well. At one point, we had 3 employees (SWEs), I fired all of them because they were slowing the building down. I do not regret that decision and if I could go back I would have done it again. I was in a rush to hire so I took whatever I could get. I still want to hire someone and have been looking but we haven't had any luck in our search. I did a webinar on Friday that I thought was just a small group thing, it turns out it was an influencer in my industry, we got a ton of view and a shit load of signups and now I cannot handle all the volume and requests. I am seeing a bunch of errors with people running the app. And although i am fixing them, I am worried we will start to get a bad reputation from this and the volume is too large for me to handle. I am talking to all the customers and corresponding with them, making the fixes, getting feedback, onboarding, demoing, etc. Way too much for one person to handle. These are good problems to have, people are actually paying us money and using the tool, its clear we have PMF but I am concerned its just not ready and we are going to lose our shot, so not sure what to do and just looking for some advice.