My ex [24M] thinks his anxiety is all my [25F] fault. 
If you are in a relationship with someone you love and you know that they love you too very deeply, can the relationship cause him to be extremely anxious all the time?  racing heart, messed up sleep, crying daily?
If your partner really loves you very much and all your fights are over dumb stuff but he always focuses on my flaws and overthinks everything I say, doesnt trust me even though I have never lied to him, always assumes the worst of me and all the people in my life, overthinks if this relationship is good for him, overthinks every fight and every conversation. Am I the problem?
Also this anxiety used to happen at the begining of the relationship even before we had any fights, he would overthink if I am the perfect one for him or is there someone else more suitable for him and he would ruminate and panic and get an urge to break up with me out of the blue but he would also be crying like he doesnt want to break up with me and we would discuss it and he would take it back. We had a long distance relationship and the world was very chaotic while we were together, I was also constantly stressed out. But even when we were together like we finally met he would still be anxious. 
He broke up with me, he blames me and he told me that my flaws and mistakes cause him to be anxious and depressed. Anytime I contacted him, he was even more mad at me, he says when I contact him he gets panic attacks and feels like he is relapsing but when we are apart his anxiety calms down. Am I the problem? Am I a bad person that causes him to be this way? 
I am devastated because not only I lost the person I love and I was thrown away like trash but also he blames me for everything and thinks I caused his sickness.