When my anxiety first started coming around when I was little, I also felt it start with my stomach to the point where I had to miss school. My parents thought it might be an ulcer, and I ended up going to the doctors. I had blood tests, and scans. All of the tests of course came back normal.

It wasn't until I was older that I realized that was all anxiety related. It still centers around the stomach, but it's not nearly as bad as it used to be.

When you mentioned about your passion and motivation fading over the years, I think that's not so much anxiety as it is simply getting older. We don't enjoy the things in excess like we did when we were much younger.

On the part about feeling sorry for yourself? You should go easy on yourself and try not to fight the anxiety. Instead, embrace and accept it. If you take a proactive approach to your anxiety, you can actually turn your feelings of helplessness and feeling sorry for yourself, into something positive. Become a student of anxiety and learn as much as you can from it.

You mentioned about watching Youtube videos? That's a perfect place to start. It really helps you get a better understanding when other Youtubers (who are mostly regular people like you and I that struggle with anxiety) are talking about how they deal with it.

Another thing you mentioned is that you have low self esteem. If you take a proactive response to your anxiety and start learning more about it and having a toolbox on how to deal with it, that actually builds your esteem. Start celebrating little victories. If you have a day where your anxiety hasn't gotten the best of you, celebrate that.

Good luck bud. Message me if you need anything.