AIO Workplace didn't submit my paperwork in time and now I won't have insurance the rest of the year

Throwaway because I've talked about where I work on my main. I'm in the US.

Basically, I work for a small construction company (10ish full time employees). Started in Feb, went full time in March. I was supposed to get to enroll in health insurance in June, and the insurance is part of the reason I accepted the job. I have a handful of chronic conditions and have been basically white knuckling it through without medication or dr visits since Feb. Paying out of pocket for meds alone would be about $300, let alone the dr visits for refills/etc.

So June rolls around and I start asking about forms, how to sign up, etc. I'm asking on a weekly basis and it keeps getting put off. Finally in August I get set up in the system needed for the forms and enrollment, and get it all filled out. According to the screen after I filled out the forms my insurance would be effective in September. Not great, but fine. In September I log in and see that now the effective date is October 1, weird, but maybe I misremembered something.

Now its October 3 and I haven't gotten any information on this plan I'm supposed to be on, so I email our rep. She emails me back that she told my owner WEEKS ago that since Owner hadn't submitted my paperwork in time (which apparently should have been within a month of my full time hire date) I'm not eligible until next year. Here's where I might be over reacting.... I told the GM I didn't want to talk to the owner until Monday because I was too emotional, and asked if I could work from home after lunch. He said yes, but basically that Owner wouldn't be happy about me working from home and he didn't know what to tell her because the insurance thing is between her and I.

I am emotional... I'm tired of my body hurting, and being off ADHD meds, and not getting the physical therapy I need. I'm tired of migraines. I'm tired of gastropareisis flares. I had strep a few weeks ago and just prayed it didn't get worse (step has put me in the ER before). Let alone the stress of freak accidents. I'm seriously considering finding another job after this, because it's not just the 3 extra months of being uninsured, it's the fact that I had to keep bugging owner to get it done and she still didn't, and apparently she knew I wouldn't have insurance weeks ago and didn't tell me. To me, the insurance is part of my total compensation package, so not only am I out the savings of having insurance, they'll also have saved over $1000 by not paying the employer half of the insurance premium by the end of the year.

I know there's nothing to be done about getting me insurance at this point, but I'm worried she's going to brush this off on Monday when we do talk. I'm debating asking for 5 more sick days (roughly what they've saved divided by what I make daily) since I've already used all 3 that they give us and the winter is always rough. I do like this job, but man, this feels like a huge fk-up in my opinion.