I work as a business analyst in major global company. I have to talk sometimes, but not too much and I sometimes stutter a lot but people dont give a fuck as you are valued for what you create rather than for your talking. If you are into excel (and other stuff like sql, dax, tableau, powerbi etc) this is the perfect job imo. It pays well, everyone is cool if you are not so much into socializing and people in business are not suprised at all if you are little weird. Also the people you find there are pretty introvertic, but little bit more open than guys from hardcore IT department and usually kind and patient people. Starting on some junior position is generally pretty easy. You need to know excel and some basics of sql and often that should be enough. (you can learn that on udemy, coursera etc)