This sounds very painful. At this point, your conviction that you are going to fail is at least partly what is making you fail. When we focus on the possibility of making a mistake, it’s almost inevitable that we will do so. You need a big boost in confidence and courage so that you can start laying a foundation of successes to change your image of yourself.
Please give yourself a break. It’s not at all unusual for a 19-year-old to still be working on separation from parents, to not have a partner or to not have had a job. It’s not unusual to have a crisis of self-confidence and self-esteem at your age, either. The issue is not what has been but what you are going to do about it now.
Here are some steps you can take to make some progress.
First, you need to get more active. If you can’t find a job right away, start building a resume by volunteering. Human services never have enough help. Look into opportunities in your community and offer your services. It will give some structure to your days and a way to be useful.
Second, find people like yourself to hang with. Not everyone is an athlete. Not everyone is ready to date. Identify a cause or activity that you truly enjoy and find out where people your age are doing it. You don’t have to make instant best friends. But you do have to start hanging out with people so you can develop your social skills and start to create a support system of peers. Just working (or playing) side by side with people will help you start to feel comfortable. Some of those coworkers may evolve into friends.
Finally, understand that we rise and fall to our own expectations. If you expect to fail, you will. If you know your own strengths and play to them, you are more likely to succeed. Check out the Authentic Happiness Website at UPenn and take the Signature Strengths Questionnaire. Identify the strengths you already have. Then work with them. These are the foundation for being more successful.
I wish you well.