It really is not unusual for those of us who have been through trauma to be unable to access our feelings. Therapists know that and are not at all surprised by it. I have been in therapy on and off for many years, and it has only been in the last year or so that the tears have come. Be patient with yourself. Just respond and process in whatever way happens in session and don't put the extra pressure on yourself about worrying about crying or about your therapist's reactions. We are much harder on ourselves than how we think our T's think of us. That's all that fear of judgement, shame, etc. coming through.