I performed as a solo pianist for several years for a living and have supported students who perform, so have many thoughts on this.
Every single performer who had been on stage multiple times has had a time where they have mucked up. That is what it means to be human. It sucks and it can be really demotivating. No one remembers your errors except the performer themselves!
People in the audience also don't focus on your errors, those that do don't wish the best for you anyway so why bother about them? Honestly the majority of people would admit they enjoyed listening to you despite the error. Those that dont enjoy your playing would probably not enjoy it even if you made no errors, they can go back to their favorite recordings lol!! The drama of the error shows we are all human and we are not perfect, people with life experience will know this and be even more on your side to overcome it.
You can do practice performances for smaller groups of people, play in public places, donate your time to nursing homes, churches, public spaces etc. Find online places where you can play for others, or just use a video camera as an audience. The more you practice under performance pressure the easier it gets and you learn to care less about errors. Getting to the point where you don't fear errors even whilst it occurs on stage will strengthen you and allow you to push through them with more clarity.
Just remember everyone has made errors on stage, those that haven't have rarely performed!