Unable to breathe

I have been depressed for a few days now, mostly because of my thoughts that keep popping up about relationship things – which are based on energy. I have been dealing with this thoughts by applying self forgiveness and researching the origin of the thoughts –why do I have them, what drives me to think that, when did I experienced this in the past, memories...but more I write, more depressive I am and these thoughts have more power over me, they are stronger, more frequent and more common throughout my day. I am starting to doubt in my application because I don't know what is happening. I don't know how to stop the thoughts and when I want to breathe, I just can't. It is like my lungs are not capable of doing the whole breath – it is almost like when you need to yawn and you can't and then you have this feeling inside you, like you are not completed, like something is missing. 

I know that by just doing self forgiveness and then not living the actual realization and corrective application, this won’t go away. But I don’t know how to release that. I still need to do a lot of writing but still…this inability to breathe normal is insane, it drives me crazy – I feel anxious because my lungs can’t expand. Now I know, how precious one breath can be, how cool it is when I can breathe. Better to get this over with, so I can breathe again.