When you have social anxiety, the primitive fear center in your brain (the amygdala) is setting off false alarms. The amygdala thinks a situation is dangerous when it is not dangerous. To change this, you need to desensitize your amygdala. You can do this through a process called Habituation.
The Law of Habituation
When you desensitize, you're taking advantage of the Law of Habituation. The Law of Habituation says "the more you do something, the less your fear it." So whether you're practicing in a lab, real-life or using virtual reality, you'll notice that your fear level will go down the more you practice. The graph below shows how the Law of Habituation works.
Habituation is like learning to ride a bike or drive a car. When you do it the first time, you're really scared. But the more you do it, your anxiety goes down. That's how it works with social anxiety. The key is to find a safe "laboratory" where you can slowly and gradually desensitize (see treatment options). Treatment programs will tailor desensitization exercises to your situation and your needs. So if you are fearful meeting people, the exercises will focus on that. If you are fearful of dating or interviewing or public speaking, the exercises will focus on that. Typically, you will be fearful of several situations, so the individualized treatment plan will be tailored to those situations.
The best way to overcome a fear or phobia is to practice frequently while being gentle with yourself. This means gradually challenging yourself, but not doing anything too overwhelming for you. Do exercises that are scary but manageable. Push yourself a bit, but don't terrify yourself!
While you're desensitizing, you should also be practicing new thought patterns. Together (1) your new thought patterns and (2) the experience of being in a fearful situation without the false alarms going off, will reduce your fear to a manageable level. The more frequently you expose yourself to the fearful situation in the right way (a CBT desensitization specialist can make sure you're doing this correctly), the more your fear will go down. As long as you're implementing this correctly and taking baby steps, you will probably see exciting progress over time. Every individual is different, and there are no guarantees, but this treatment is effective for most people.
If you want to try this on your own, here is a worksheet that can help you design your own gradual desensitization steps.
Sample desensitization exercises that increase your tolerance of scrutiny
To desensitize, I recommend that you find ways everyday to increase your tolerance of scrutiny. Social anxiety is caused by a fear of negative judgment and a low tolerance for scrutiny. So the more you can increase your tolerance of scrutiny, the better.
Here's an exercise to try (ask a friend to help you): Sing happy birthday to your friend on a street outside a store. Or hum in a store while shopping. Notice that nothing bad happens. One of the things you want to teach your brain is that scrutiny does not have horrible consequences. Tell yourself, yes some people looked at me, but did anything really bad happen? Am I really paying a price for this?
Start off doing scrutiny exercises that you can handle easily. Find things that are a bit of a stretch for you (just outside your comfort zone) but not overwhelming. Something you can handle but is slightly uncomfortable. Then go to the next challenging situation. So if the singing happy birthday is too much at first, start with something easier.
Here is a list of scrutiny exercises you can try:
Try to invite scrutiny at least once a day. Remind yourself that nothing bad happens. As you get comfortable with the easier exercises, try to do progressively more challenging exercises.
Check out the social anxiety course that explains the entire process in detail with animations. You can also take the free mini-anxiety course or download the cheat sheet to get a high-level overview.
How to overcome social anxiety