cc24ru, pining after your ex-wife reminds me of your involvement with your APs. It's a form of avoidance (and this particular form is damaging to her because the white-knuckling will wear out eventually and she will have to deal with the burden of your once-a-year giving in to temptation to try to contact her. Don't do that anymore!).
Your pining is the Land of the Lotus Eaters in the Odyssey, Hamlet's endless indecision, your particular form of running away from living life and numbing yourself. You were forced to face the feelings of worthlessness and shame from infidelity when it came to light, but that helps you avoid the deeper and more poignant feelings of worthlessness and shame that came earlier in your development. So you're hanging out in the known shame instead of venturing into the unknown.
The big problem is that in shutting down whatever deeper feelings you want to avoid you are shutting down the fullness of life, and life is WONDERFUL! It makes me so sad to imagine you wandering through the woods, crying in despair. Nature is usually healing, because it is so full of life and wonder and amazement. But your despair is so profound you are not available to a huge dose of healing life.
The suicides you have been close to . . . that is probably the tip of the iceberg. You must have experienced profound trauma, or at least been close to it. I can't imagine what kind of sense a 14 year old makes of that kind of proximity to suicide. And I'd wonder if you are chemically susceptible to despair.
The good news is that you are not worthless, not shameful, not insignificant. You are a worthwhile, important, valuable human, made just a little less than God (!). Or if you don't believe that way, you are the tippity top of the pinnacle of survival of the fittest, the very best that nature can come up with. I think your work is definitely with an IC, someone you can trust with your deepest fears, to identify where those feelings are coming from and start to learn to fight against them. Or, if you are open to it, a really good pastor. Those feelings may never go away but you can identify them, name them, understand where they come from, argue and fight against them, and your recovery time can be faster. And then you'll be open to the wonder and beauty of life.
For a start - the podcast The Happiness Lab with Dr Laurie Santos. It's research-based practices to change your mindset and habits. A little something to get you started while you find a trusted person and develop a relationship with them to help you.
Life is both wonderful and awful, friend. In all its fullness. The awful can make the wonderful more wonderful, if you let it. I hope you don't sleepwalk through life any longer.