Being overwhelmed is like sleep-walking inside a self-inflated bubble of emotion. Its very comfortable, but its no good. Because it is a bubble, and when it bursts, your sleep is broken, you find yourself in an unknown place with no clue of how you got there.
An overwhelmed state of mind is often the reason behind us saying things we later have to bite our tongue on, (how many times do we say yes when we ought to say no?) and doing things we later feel embarrassed about.
There is a single, simple solution to both sleep-walking and being overwhelmed: being aware.
Take a deep breath, and keep it real.