The proper prep work for any type of paint will kill your allergies. You need to scrape off any loose paint and then sand the old down before applying new. If you are applying a water based paint, then you'd need to sand off all of the old paint, or use an oil based primer and then top coat. Anything durable for concrete won't be low VOC.

I'd suggest putting down a vapor barrier/cushion and installing a light colored laminate over the concrete. It will be easier to walk and stand on, and as long as the floor is flat, you won't need a lot of prep to do it.

If you suffer from asthma you should probably avoid field applied finishes and flooring made of wood fibers bound together with synthetic resins. The best flooring is probably real hardwood with a metal oxide or urethane factory finish.

hmmmm. good points.
I won't go to the expense of installing a hardwood floor- for a few reasons, IE this is a cheap condo that I will sell when my 'up north' house sells, I use my bedroom for a craft room and want something that is durable, putting in hardwood won't be a financial good move as I will sell and wouldn't get my $ back.
Has to be paint....

Hire someone then.

You should be able to find even a handyman that can paint a floor for you.