I really appreciate the quote as one of my first impulses when I woke up was a desire to delete the post and try to hide everything away. I realized I forgot to ask someone to quote it so I was very thankful to see someone did so anyway. As for trying to deal with the fear/anxiety with avoidance, it was an important part of the process in my original therapy, but that was tempered by an understanding that I still needed to develop active coping/defensive mechanisms. I had to rewire my default chain of thinking so that I could be exposed to triggers without getting sucked into the vortex of despair. Otherwise I would be too dependent on external conditions I couldn't control and a regular life means that I will get exposed to triggers, so I wanted to be strong enough to acknowledge and reject them.
I see enough of myself in your description that I'll share a bit about my therapy in case it helps in some way. One of the hardest things I had to accept was that I had a guilt-complex and that it helped to fuel some of my self-destructive tendencies. For example, I lost a lot of weight during my depression because I had no appetite and eating felt pointless. I would try to force it down, but that would often lead me to vomit (anxiety attacks also caused me to vomit). But I also got a bizarre kind of pleasure out of it, because I felt like my suffering somehow compensated a bit for my privileged first world existence. When people remarked how worried they were about my weight loss, it would make me feel better, not worse. It felt like proof I was truly suffering, and I had to suffer because of how good my life was compared to the third world.
I did not want to admit it for a long time, but I was being masochistic and guilt was the tool; I would even intentionally make anxiety attacks I was coping with worse so that I would vomit. It's hard to recall and explain the motivations precisely. I was suffering, but it was self serving suffering motivated by my own desires, I wasn't actually suffering for the third world. Why would anyone there know or care that I didn't eat that day or that I threw up my last meal? It didn't change or affect anything or anyone except for my life (and others in it). "Real" guilt corresponds with corrective action, not self-flagellation.
The problem is there's no one to apologize to nor is there any true absolution for inequality; there's nothing I can correct, it's just the way things are. Knowing I couldn't impact the dynamics of global inequality, I had to decide how I wanted to react, do I not deserve to live at all or do I accept reality and move on? If I truly felt first world existence was immoral or unjustifiable, then I should kill myself or move to the third world, but self-harm and masochistic guilt was not an honest response. That was my attempt to have both slices of the pie, to live in the first world because I 'bought' in through suffering.
That also tied into a lot of my high concept philosophical thinking that was just self-harmful and truly pointless. What was the point of getting into those weeds if it was only going to hurt me? I felt some duty to 'honesty', that ignoring these "truths" was wrong and I had to confront them, no matter the pain and suffering it caused me and those I had relationships with. Giving up 'big' philosophy was one of the most important things I had to do to survive and I still struggle with it. But for me, continuing down that road was a dead end, I wanted to live, not to live like I was dying. I have not cracked open a philosophy book in many years and I am the better for it. I don't want to imply that I got better simply through self-realizations or appraisals though. They were necessary steps in my recovery but not sufficient by any stretch. True recovery meant extensive training to rewire my thinking and behavior from default negative to default positive, simple and cliched it may be.
Finally, I would say that although I am not a Buddhist, I identify with a lot of Buddhist teaching which I find to be a realistic and practical appraisal of human experience. I went to Jesuit schools but had a Buddhist relative, though I would not claim to have more than a passing knowledge. Although the Jesuits helped strengthen and affirm my thirst for justice, Buddhism helped me realize that kind of thirst (tanhā

is itself a source of suffering. A desire for answers, for purpose, for identity, for justice, all these kinds of cravings are a well of suffering; they are a black hole of need that you will never be able to truly satisfy, because it is the continued existence of the need itself that is the problem, not a perceived lack of solutions or answers which can only ever offer temporary relief. An unyielding desire to be happy can be just as harmful as an unyielding desire to not be sad. It's a very different way of thinking compared to Western tradition, and I have found it helpful in getting away from the existential angst that Western philosophy tends to create.