Note to self:
Try to catch myself - while in a conversation with someone - starting to feel the point at which I percieve said someone is acting as if he/she is not approving of something I say or act. Watch how I react to that (defensive, adverse, fear, uncomfort etc...) notice also body reactions (heartbeat, sweat, increased temperature etc..). Figure out how to stop automatic reflex reactions and take a different internal/external behavioral approach.
Related: Looking-glass self
keep in mind that your reaction depends on how important the person is to you. iow, the kind of relationship (friend, co-worker, parents, stranger etc) has very often an influence on the reaction.