I have had to deal with this. Resetting expectations with health issues, family and personal challenges and growth, finance, unemployment, etc. Huge keys are honesty with self and others, kindness (the whole true Golden Rule), prioritizing and solving problems one at a time, not giving up, etc. (Edit: others here also have some ideas that can be helpful -- like maintaining good health practices, etc.)

Still, for me, and I think after a certain point for anyone, there are big some prerequisites, or the good conventional wisdom can break down and be insufficient. Prerequisites including things like like having balance and purpose in life, and a perspective and way of knowing that things will be OK in the long run, that hard things are OK for now, where to find help and solutions, and endure well through the unsolved (for now) things, how & why. I've written much more elsewhere (see profile; nothing for sale but can try answering qs). It is hard, possible for anyone one step at a time, and worth it.