okay, so, i can’t give any concrete advice here cause obviously i don’t know all the nuances of what your kid is going through, and even if i did i’m not a psychologist or anything. BUT what i will say is that your son sound exactly how i was at age 18. crippling social anxiety, couldn’t look a stranger in the eye without turning bright red and couldn’t order from a drive through without stammering my way through it, struggled to fit in, etc. first, i’d recommend therapy. that can be expensive, so i get if it’s not possible, but if you can manage it that really would help. when you’re that socially anxious you exist pretty much in your own head. no matter how much anyone tells you “oh don’t worry, your classmates (/etc) are just people, just talk to them like you would your one friend,” they probably have a deeply held belief that they “aren’t normal.” they see their peers being “normal” (ie: going to parties, working service jobs where they have to interact with strangers constantly without any stress, having girlfriends/boyfriends, etc) and the more their anxiety isolates them from those experiences, the less “normal” they feel, and the more anxiety they’ll have if they enter into a situation where they could potentially find those things. it’s really a self fulfilling prophecy. a good therapist can help break those self loathing/self alienating thought patterns. not instantly, mind you, but over time if your kid is able to put in their end of the work therapy wise they will grow more comfortable with themselves, and slowly but surely have an easier time socially. also: definitely can’t say with 100% certainty i recommend this cause i’m not an expert and i don’t know your kid, but i would certainly consider getting them on antidepressants, anti anxiety meds, or both. it’s hard to break those self loathing and isolating thought patterns if their brain chemistry has them constantly in panic mode. anyway, i’m probably talking out of my ass to an extent but based on my experience this is the advice i’d give. good luck to you and your son. a lot of people struggle socially in their late teens to early twenties, so make sure he is aware this is a common thing and not him being “a failure” (which is what i’d frequently refer to myself as to my parents when i was in this situation)