No you can't - in order to work in any capacity in Qatar you need a sponsor and be registered with the Min of Labour. In your case, probably the Min of Health too.

Anyone taking in $$ for services rendered has to be registered. I don't know exactly how that works with a spouse sponsored by her husband, but I doubt if you would be allowed to work for yourself - that would mean a Qatari business owner/sponsor wouldn't be earning their "share" of your labour. In order to set yourself up I would think a Qatari sponsor is required at least

The PRO at your husband's company should be able to give you some advice in this respect. An inquiry at the Ministry of Health might be informative too.