How would you handle yourself if you are taken by surprise and overwhelmed by one, two, or three opponents?  What would you do if you were being punched and kicked continuously?
Most people, especially without any training, would most likely freeze and become victims to violent crime. Others would panic and get scared, resulting in making a grave mistake.  On the other hand, there are those who would know what to do in those types of situations, and can come out the victor. How can you be one of those people?
First things first; how to stay out of that situation all together.  Be aware of your surroundings always. Do not be afraid to keep your head moving, looking for any potential threat, focusing on behavior and non-verbal cues that raise a red flag.  If something appears to be threatening in your mind, trust your instinct.  Do not just blow it off.  Overtime, you will not even know you are doing this, it just comes naturally.
There may be that moment you do come across a situation you are caught off guard.  What should you do in those situations you actually do get jumped?  The human body can take a good beating, especially if you are athletic and strong.  It all comes down to how you respond mentally.
Reaction is important, but there are proper ways to respond as well as improper methods.  Let’s focus on some “do nots.”
Do Not
Panic:  When you panic, you respond in a way that is hasty and dangerous.  Rationality is thrown out the window and you do anything you can to survive, usually the wrong thing.  Panic is also based out of fear.
Freeze: Another form of panic is to freeze.  You are not sure what to do, so you just stop.  That will definitely get you killed or seriously injured.
Do’s
Keep Moving: If you can, move your body.  If you can move around to gain distance from your attackers, the better you will be.  A moving target is much harder to hit than a stationary one, so move those feet and blade your body to reduce the target areas.
Block: God gave you arms, so learn to use them to block.  Protect your vital areas, such as soft targets, chin, and organs.  Keep moving.
Counter: Look for openings in your attackers guard to push, kick, or punch your way out.  They will not be so focused on defense because they are so focused on aggression.
Shield: Use an attacker as a shield from others if there are multiple attackers.  Continue beating on him, while creating space from the other attackers.
Run: If you can get out, run and create some distance.
Training Tip
How do you prepare your mind to deal with this?  Just like you do with everything else; you practice. Grab a couple of trustworthy friends that will help you train, or join a self defense gym that teach this type of training.  Make sure you have safety equipment: gloves, helmet, rib guard, etc.  Have your partners throw a flurry of punches and kicks, while you learn to block.  Disclaimer, you will get hit and it will be fun.  Just learn to be defensive.  Think of these questions while you are training.  How does your mind process getting hit?  How does your mind respond?  You will be shocked at first. It is better to do this in training than it is in the field.
Next, add some counter options.  Look for areas where you can counter your opponents and learn to move, counter, and create distance.  This will help you learn to fight under intense pressure.
Lastly, try doing these drill with multiple attackers.  Learn to use an opponent as a shield.  Continue hitting him while protecting yourself from the other fighter(s).
Disclaimer: You should start out slow and focus on light contact.  There is a progression on how you do this, because if done improperly, injuries can result and it defeats the purpose of this type of training.  More importantly, you should have an experienced instructor to supervise so you can train in a safe environment.  Fighters4Christ trains in some of these methods, so I would recommend giving us a try.