Just graduated bachelors comp sci. Didn't get into MS. Confused what to do
Get a job. You write that you have really low confidence, are really bad with interviews, are socially awkward, etc. These are not reasons to not get a job. The point is that even if you had been admitted, you will still have to get a job after you finish your MS degree. Since you will have to face these demons eventually, you might as well do it now. These things may be scary, but they can also be conquered (see Workplace.SE for more advice). It can even be a blessing in disguise - you might decide that you'd rather keep working than go to graduate school. Remember also that the longer you wait, the less employable you become.

You could take a gap year also and do all the stuff you mentioned, but you would be spending money without earning it. That is not sustainable. Unless you are independently wealthy, you would be burdening your caregivers for an extra year. Your caregivers are likely much older than you (i.e. they need to think about their own retirement). Meanwhile you'd be spending one of the best years of your life on things with uncertain long-term benefits. Is that responsible behavior to you? 

You can't postpone growing up forever. Get a job.