I'm very bad at recognizing body language or emotion, or picking up on what someone means when their wording is even slightly vague.

Please note that this is just pure speculation and I want to make it clear that this is not a diagnosis since I don't know you and I'm not a professional, but it sounds like this may be slightly different from Social Anxiety Disorder. Have you been tested to see if you're on the autism spectrum? The fact that you're struggling with social cues and linguistic pragmatics is something noteworthy since those are not necessarily symptoms of social anxiety disorder (though many symptoms do often overlap).

It's of course possible that it's just anxiety that's preventing you from focusing in social situations, but there may be something else going on. Either way, it might be very helpful for you to talk to a therapist or another professional about this.

Good luck!