Its like the phrase "birds of a feather flock together". but your particular quotes means that if there are lots of people with a similar problem, they come together to support each other and show they are not alone. It's like alcoholics anonymous. they all have a similar problem, and meet with each other to talk about the problem and help end their problem.
This is a great quote, and means that many hands and different view points can solve problems. 'A problem shared is a problem halved' is another similar quote worth remembering.
The basic gist of it is that there's always hope no matter how broken you think you are as long as you make an effort and work hard on whatever the issue is. I like it.