You'll know when you've gone deep enough, because the pain will shift and there'll be an infusion of light in some way.

For the next part, my sense is to involve an Openhand Facilitator. It's deep, and it might be wise to have someone hold the space while you explore into it. However if you truly feel you can deal with it, we could continue a bit more here. It's your call. If it gets difficult - I could then connect you up.