@thestrugglingturtle Hi, a couple of tricks I have found that really help in social situations is to always try to be nice to others, like complementing them when they come with a new haircut, smiling when you see them in the hallway, and offering to let them borrow your umbrella if they are going out for lunch and it's raining. Simple things like that really go a long way in letting people know you are a nice person deep down, and most people will reciprocate the kindness, and some people will even start to go out of their way to be your friend. you also mentioned you stutter when you are nervous, well many people do uncontrollable things when they are nervous, the key is to practice talking to people so you are eventually not nervous anymore, and your stutter will diminish.
Oh and about the no girlfriend thing:
Girls love heartfelt complements. For example, if a girl at work is very good in front of patients so that all patients love her, you can smile and say to her "You are so good with patients. They all love you. I wish I can be that natural around patients." Everyone loves hearing the first part and will want to help you after hearing the second part.