I don't know how to fix your situation, but I do know what helped me, so I'll tell you that and maybe something will be helpful to you. The first challenge is

I don't know how to fix your situation, but I do know what helped me, so I'll tell you that and maybe something will be helpful to you. The first challenge is to recognize your foe. You feel stressed and anxious at work, so it must be your job. You aren't achieving your goals as fast as you like, so it must be you aren't working hard enough, or you're not smart enough. You don't like anything you are doing, so there is something wrong with the world, or you don't have an adequate answer for meaning of life questions. For me the first step in getting better was realizing that the problem was exactly none of these. The problem for me was balance. A lack of balance in my life was directly affecting my health which in turn was directly affecting my emotional and psychological well being, which made it pretty tough to deal with life, especially one as intense as I had created for myself. I got better by getting balance and getting my health back. I quit smoking. I quit my job because it took up too much of my attention. I got a new job at a company with a culture that respects my life outside of work, but I gave myself a month between jobs to read scifi and work on fun projects. I started running. I started a diet to lose weight. I let myself play video games on occasion. I spent time on projects that were interesting and fun to me, not just projects that advanced my career. I went on dates with my wife again. And then I just waited. It took a long time to get better. I ran my first 5K a week ago, about two years after I started). It took me two attempts to quit smoking, but it's two years of no cigarettes on the 29th. It took two years to lose the 40 pounds I put on. I emerged from my mental funk after about a year of this treatment. Then I almost did it to myself again, but this time I knew what was happening and stopped myself before much damage was done. I'm sure other people could have knocked out these goals faster than I did, but that was not the point. The point was to learn how to have balance in my life. And now that I have something resembling balance I have my health back and my problems, (at least what I thought were my problems), seem to have melted away. I'm less stressed at work, I'm less concerned about achieving career milestones and I'm far more confident about my own abilities. I still have meaning of life questions I'd like to dig into, but they seem less pressing, less looming and gloomy, and more inviting. I still have stress, I still compare myself to others, and I still work too much. But what I experience of stress and anxiety these days is just a shadow of what experienced back then. And there you have it. The foe I was looking for was me the entire time. But the solution wasn't to beat myself up or too work harder or be more ruthless. Instead I needed to learn how to find balance.