We all go threw some type of inadequacy , it's because of age, how we where raised, with women are periods are a big part of it Sometimes it becomes just a habit. Remember that you are unique and there is no one like you, so to me that makes all of us special. Next time you have a conversation talk about something fun that makes you both laugh, also you may want to start working out. You need things that help you to stop thinking about everything, so stay busy, busy, busy
I suffer from the same thing. It is even worse in my professional life. Whenever I speak up in a meeting, all I can think about afterwards is how stupid I sounded or like you said, just overanalyze every detail of it. Prior to meetings or interviews I will get myself so spun up and nervious, I will talk myself out of going or talk so fast nobody knows what i have said... One thing that has help me a lot... When my mind starts racing like that and over thinking every detail... i remind myself of just how little people really retain what you say or do cause most of the time they are thinking more about other things or how stupid and awkward they came off sounding. After that conversation is done and gone, usually you are the only one still thinking about what you said or did. If you ever asked a third party about all the questions you had in your head about what you said and what you did, and how you came off and if you seem this way or that way.... they would not even know what you were talking about or not have even noticed the nerviousness or awkwardness that you were feeling.
I have bad anxiety too and when it happens I too overanalyze everything. Each word and action I pick apart and wonder what the others thought of me. It made me so paranoid that I think that no one likes me or that everyone thinks bad things about me or they are against me. It freezes you up to the point that you second guess yourself and feel inferior to others and so you stay at home and become a recluse.
You might want to try an antianxiety drug, I know because that has helped me to calm down and act "normal." in my thinking and actions. I used to use it daily sometimes several times a day but eventually as I got better I found that I didn't need it as much and take it every once in awhile. I have had anxiety since childhood so I know this will be with me for the rest of my life.
You might want to join a support group here online or in person or do talk therapy with a counselor on a regular basis so that he or she will give you coping mechanisms for you to try in social situations.