Employer Rescinded Job Offer

I applied for a job in early November and they called me for an interview the next day. I had the interview the same week and it went really well. I’m very knowledgeable for the position and they told me at the interview they would be sending an official offer the next day. I got the official signed offer letter and they began the onboarding process, such as signing up for direct deposit with my account information. They wanted me to come in a week later with my social and birth cert for the paperwork. Well, during that week I was in contact with them most days going over details. I discussed with them a couple very simple accommodations that would not in any way affect my ability to do the job. The HR rep told me she would get back to me but that it would be no problem because they’ve accommodated more in the past. Then they call me a couple days later, and said they are rescinding my job offer because the person that was in the position previously decided “not to resign” but that I could perhaps have the position in a “couple years when my (accommodations) are no longer a concern”. This reeks of discrimination to me, but I’m not sure if I am being over emotional about it because I resigned from my previous position after the signed offer. Any advice would be appreciated, thank you!