What do I do when I'm stuck in family business that is currently hurting my health and holding my career back?

I am a young educated engineer graduated from one of the top schools in Canada with diverse work experiences and skill sets. For the last year, I have been helping our family businesses but recently fell ill due to toxic mold in a hazardous work environment. In addition to that, our family businesses are disorganized and poorly managed but should be profitable if we (mainly I) put more effort into it. My problem is that I don't want to lose my window of opportunity to transition into a rewarding career by sacrificing any more time and health. I feel that I already sacrificed more than I am comfortable with but if I leave, the businesses and my parents will most likely fall apart.

Family and entrepreneurial values vs. Selfish Career-oriented ambition???... any advice would be greatly appreciated. This is going to be tough but reality check - it's not your business. It's your parents (I assume) and I also asume they've run this business for a long time without you right? If you leave and it fails it's not your responsibility. You have to do what's right for you.

Now if you really want to run the business than at least ask for an ownership stake so you can get rewarded for your hard work. If it's not something you want to do you'll regret spending a lot of time/energy on something you don't find rewarding.

don't feel guilty for wanting to have your own life and good career.

options include:
help find a qualified manager to help run the business
help devise a good business plan that they can follow-maybe act as a part-time consultant
if the business will fall aprt without you, there is a problem-maybe staying is just prolonging the ineviable while cheating you of a career to trained for and chose-perhaps they would consider selling the business?
find a small business association that will provide good advice at low or no cost.

we all owe things to our parents, but not our lives. don't feel bad for wanting the life you deserve.