They may not be the same "people" but you can learn from what happened and not make the mistake again.
In those relationships..... you can do a relationship again, trust me you will love again .... but it might not be with "that" person.... maybe it will be with someone much better for you or you never know.... maybe when you start to work on yourself the two of you will come back together.... If it is ment to be it will happen... OR.... you become healthier from those relationship and work your recovery and look back and wonder what the heck you were doing with them in the first place?????