2 year old has extreme stranger danger, help!

My daughter turned 2 on December 1st, and for awhile now she has been terrified of strangers. This happened sometime after her first birthday and she still hasn’t grown out of it. She’s only comfortable with my Dad, me and her father, and my Grandma once she gets used to her, and sometimes my uncle. Most of the time she just screams at them and runs away and hides. I have been taking her out to more places but it hasn’t been helping much. She hasnt been around other kids her age yet, I’m a SAHM and finally am getting a new car next month so I can try to find a play group. I’m just worried they won’t take her because of how afraid she is of people. What can I do to help her socialize more? Even when we order food, at the sight of a stranger at the door she cries and runs to hide. Her doctors are now beginning to tell me they think she has autism because of her anxiety and her speech delay, however she’s very loving and loves to play. I’m worried they’re going to misdiagnose her because they cant properly evaluate her for autism because she only cries at the sight of the doctors. Advice??