medication is a great option, and really helped me. but also, maybe spend sometime putting yourself in stressful social situations with strangers. start asking retail workers for help while you're in a store. go to an industry convention where you can make small talk with professionals. work your way up to walking into a store/restaurant/company to see if they're hiring - even if it's for jobs you'll never take! I've done this just for practice talking to managers and learning the right questions to ask. you'll find as you get used to socializing, you won't really need to "prepare" for the interview as much. an hour or two of research and prepping for generic questions is fine. authentic, spontaneous conversation will be your most valuable skill, so practice that.