Just remembered. You may know of the Placebo effect when you take a fake tablet but convince yourself it is going to have a positive effect and it does. There is also the Nocebo effect which is the reverse. You take an effective tablet but you convince yourself it is not going to work or even make it worse and it does.
Research has measured the effect of attitude on the Immune System. A positive attitude boosts the Immune System, a negative attitude suppresses the Immune System. So stay positive everything helps. Look at Steven Hawking, when he was diagnosed with MND they predicted he would be dead in 2 years, that was 50 years ago! Be positive.