Hi EmmaL,
Welcome to the Forum.
As you've found chewing over the same old issues is very exhausting. It's as if those issues which happened in the past aren't really in the past, and are affecting the present. Sometimes a different perspective on past events is needed.
When we chew things over like that our mind is emotionally aroused, and we experience anger or depression, or whatever emotion is appropriate. For past events which we can't now resolve that emotion is unresolved - at night our dreams deal through our imagination with the unresolved emotions. Although we're asleep this dreaming is actually quite tiring so we awake exhausted. Your mind is active on the same old issues and the cycle continues. You can read more on this on
Depression Learning Path
As you've found counselling which just goes over the same old issues actually just feeds the cycle - creating more emotional arousal and chewing over the issues.
As regards resolving the issues, one thing that many people find helpful is to start to see them in a different way - here's something you might try, most people find it works better when they close their eyes.
When you're feeling relaxed and have some time to yourself, imagine seeing those old events as if on a TV screen or a movie, so that you can see yourself in them, at a distance over there on the screen. You can move the screen to any place that allows you to feel more comfortable, or allow yourself to move further away from the screen.
When you see yourself in those old memories, you can ask yourself something like: 'what is the learning in that old experience, the learning of which will allow you to move on and put those unhelpful feelings behind you?'
Notice how you feel differently about the situation once you can see it in a different way.
Another thing that you might consider is seeing a therapist who uses a different form of therapy from the one that you've seen - A therapist who can assist you to feel more comfortable about those old episodes, so that you can put them in the past where they belong. Let us know whereabouts you live and someone here may be able to help.
Best wishes.