This sounds worrisome. You feeling like a failure and fear from doing social interaction because you probably isolated yourself from any social interaction for long time, the only way to break this fear is to start interacting, I hate it, but nonetheless do it. WIth it you will learn how to hide your stutter, what are the best ways to avoid blocking for instance, etc. And on top of that, seek mental help, a psychiatrist will it lay down better. For give my english skills and if I sounded condescending