Somatic symptom disorder

Hello everyone! My ex boyfriend was diagnosed with somatic symptom disorder and depression. He is experiencing different symptoms for almost two years and this started a month after we started our relationship. Can our relationship be the cause of his SSD? I did nothing but support him and give the attention and encouragement to get better, but he says that thinking at me and loving me makes him this way. Nothing bad happened between us. He has this stomach pain that never disappears and many other depression symptoms. He started cognitive behavioral therapy so we broke up for 2 month because that was suggested to him but he is not getting better.

I really can` t understand why this happened. And i blamed myself for doing this to him and making him like that although i never wanted. That got me depressed and for a few months I was feeling just like him, i couldn `t eat, couldn`t sleep, couldn` t concentrate on my work because it was that blame and that hope that thing will get better and we can both be better. I really hearts that we love each other so much but can` t be together because that hurts him.

Can I be the cause of his suffering? Or what can cause this? Did anyone experienced this and how did you get through this?