Interesting thread, i have similar experience in having been in some dysfunctional relationships in the past. And have been thru incredible pain in the past due to this eg experiencing abandonment etc.
However i have to be honest and say i no longer carry any grief in relation to past relationships. I found practising meditation taught by the Brahma Kumaris helped immensely, (they have FREE seminars, and courses on meditation, positive thinking, self esteem, womens workshops, spirituality and men etc, everything is free of charge also ), They have a centre in brighton. Also i have found working the 12 step program has helped to let go of past hurts. There are fellowships for relationship issues etc eg Coda (codependants anonymous) and others, which i have found really help to resolve past grief etc... Might write more on this later as think its a very good subject to discuss more