As someone who suffers with health based anxiety and who used to spend a lot of time on medical websites catastrophising my symptons I have found that switching my obsession (which it was) to focusing on how I can improve my health and researching this instead has made me able to cope more with the withdrawal and feelings of loss from a subject that controlled my life.

My mind still thinks I am taking control of my health problems which satiates my anxiety somewhat and I do not feel so lost without referencing a subject that was such a big part of my life.

Quick example: Blood pressure, I have my own monitor and read everything about blood pressure, sometimes my diastolic reading is above 90 so my anxiety kicks in and I panic that it is too high and my heart cannot take the strain etc and I will have a stroke. I would spend hours reading the minutiae of how this could kill me. Now I spend time on sites telling me how to reduce my blood pressure, how to control it and feel healthier and live longer which changes my association with the problem and although not eliminating my anxiety it does reduce it.