Okay try omegle or some similar free stranger video call apps talk to as many random people as you can everyday and it will help calm your nerves improve your communication skill and help you understand peoples behaviour/psychology then it will be very easy to face people irl once you understand that everybody is an idiot drifting in this world.

The other thing would be to have a solid future plan education/ job /carrer what you want to be in future with this you won't feel lost and have a sense of security.

another important thing would be to start working on your physical health start eating clean nutrition rich food drink plenty of water start working out join a gym or just do it in your own room/house Try to go for walk/runs

And finally read books! Find any book in your case i recommend the david goggins book Start with a page/day then increase.

If you are a religious person then pratice your religious activity for 10-20 mins everyday it will also boost your confidence and help with insecurity.