“..my limited understanding so far is:
Living a moral life is the foundation layer.
The focus of Anapanasati should be about purifying mind rather than calming the mind through breathing meditation.
To sustain niramisa sukha and avoid going back to sensual desires, one needs to comprehend Anicca, Dukkha, and Anatta nature of life (which in turn helps live sustained moral life). This I understood from listening to the discourse but I don’t think I comprehend what it involves yet.”
That is exactly right.
– Yes. It may take some time to understand the Anicca, Dukkha, Anatta nature of life.
I am also glad to hear that your symptoms have improved. You will be able to not only get rid of them but also to experience some “lightness in the mind and the body” as well.
– Also, living a simple life is beneficial too. Attachment to material things gives an illusion of happiness but carries with it a lot of stress. While there is no point in subjecting oneself to hardships, trying to live a luxurious life (doing things in excess) can cause stress too.
– That is the “middle path” advocated by the Buddha.