Sounds like you need to explain to your T just exactly what your going through.
Make that the focus of your next session. You drive, tell your therapist this is something you need to discuss before you go any further, because there is always the chance things,might get worse before they get better.

Ask about self soothing,grounding techniques and mindfulness,these are all things designed to bring us back to the present when we feel we are slipping.
My pdoc does not allow between session contact under any circumstances however he would never leave me unable to cope, so maybe if you can just find the courage to ask.
This is of course just my 2cents worth,but all the best.
Take Care.