In your own words what happens if homeostasis fails?

If homeostasis fails, the organism could become dysfunctional, develop illnesses due to vulnerability to various microbes and/or die, simply. Homeostasis is the act where the organism strives to balance out its internal disposition. This mechanism helps the organism survive through various environmental changes. 

If homeostasis fails, the organism will become a disaster in a sense, and it can result in heatstroke and/or hypothermia. Failing to keep your energy balance can result in becoming overweight or developing type 2 diabetes. Hope this helps you out!

Yes yes yes very good