I constantly feel like i can't breath properly

For 3 days now I have been thinking that I can't breathe out of nowhere, And as soon as something bothers me a little, I get very anxious and the feeling increases.

We went to the doctor and they confirmed that it is not a heart problem, but it is taking away my ability to want to even be awake.

I don't know what to do. I have OCD traits, could it be that I got obsessed with the feeling of drowning?