Do I have a case against my former employer?

I got cancer & had surgery in April of this year. I worked through an excruciating 6 months of chemotherapy. My co-worker & I decided to trade places at work (veterinary hospital) once I got back from surgery, she was a receptionist & I was a veterinary technician. I could no longer perform the duties of a tech. The owner, nor the office manager had suggested it. My cancer went into remission early Nov. but I still have my port (IV device implanted in my chest). My boss had put me back in the kennels, knowing I couldn't perform some tasks. 2 weeks ago I was laid off due to "Company downsizing", but I was laid off on Mon. & by Thurs. there was a new girl starting to replace me. I feel I was discriminated against because of my cancer & inability to perform some tasks (like bathing an angry cat with claws & teeth or lifting a 100lb dog that's flailing around). I have been approved for unemployment, it's not much, but it helps. I am a struggling single mother of 3 & I need some advice on what I should do. Do I have a discrimination case against her?