Stress is a scary thing and can cause people to act and react out of proportion.
We've all had times in our life when we're dealing with a stressful situation. If you're lucky, you have friends and family helping you get through this time, but if you're not careful, and snap at them due to the stress, the people you need most may be driven away.
If you find yourself going from zero to a hundred too quickly and/or just yelling more often than is normal, really stop and take a deep breath. Spend some time alone figuring out what is the trigger. Yes, the stress...but beyond that, what? Did the person say something that touched a nerve? Did they react in a way that you're oversensitive to given your circumstances?
Knowing what set you off may not make it go away, but will hopefully give you enough insight to not drive all your support away.
Have you seen this happen or been a victim yourself? What helped you?