I think what you described is just normal nervousness in social situations.Everyone experiences anxiety in different ways and that's what it sounds like to me.Try not to read so much into every little thing and analyzing yourself.If you're going to analyze it,reflect back on the thoughts running through your head when it happens.Chances are they're negative ones that will just make it worse.Learn to notice them when they happen and change them or at least stop them.

You have PTSD,you have a new job,of course there's going to be anxiety and stress at first.Give yourself time to get into the flow of all these new things going on in your life.

Are you keeping in contact with your therapist through this?Are you talking about all of this with him/her?Are you asking them for suggestions?Are you using the tools you have learned?