what to do about possible toxic mold discharge from a diy sanded light fixture

I live in a small (40 metre squared) rented apartment and do crafts and other work full-time out of my front room. I recently purchased a second-hand floor lamp from someone for a DIY project. The lamp smelt a little fusty, but I thought no more of it. As part of the project I had to sand some of the plastic light moldings, to prep it for repainting, which I did with a light grit paper; however, after doing so, I had some irritation in the eyes, developed a cough, slight rash on an irritated part of the skin...and now, five days later, after pulling an all-nighter, am in bed with a headache, blocked nose, and flu-like symptoms which ease slightly when I go outside or lean out of a window. The lamp itself I long since removed from my apartment. I went to see the person I bought the item from and discovered it was kept in a basement room that smells to me like there might be some mold in it. To cut a long story short, I'm worried that I lightly sanded a plastic fixture contaminated with myotoxin producing spores, which I think inhaled....and am wondering about the seriousness of the situation and what I can do to respond. I work in the room every day and now, five days later, I imagine I'm reacting an odour in my room, which has a large mat, a couch, and an armchair, and books right by where I was lightly sanding. Is it even possible for contamination to occur comprehensively in my situation?

I cleaned the floor with household cleaner, beat the mat, used some foam cleaner on the upholstery. The room is full of electronic equipment for my small business that I've gradually purchased over the years, live on a very very tight budget, and can't afford to have items spoiled. The books too are valuable. Any sort of advice on how to approach the situation would be great. Is it possible for people working on items or old furniture in their shop or at home to spread significant toxin-associated mold from an accidental purchase? I know items in mold infected houses can be contaminated, but heard that removal of the item is enough to deal with the problem if something triggers a reaction.

In this case, having lightly sanded the item (for about 20-30 seconds) in two small places, I wonder what measures I might take.