1. Endurance - defined as the fact or power of enduring an unpleasant or difficult process or situation without giving way.

Now "without giving way" can be taken with a bit of liberty as we all give in, break down, give out, in all manners of speaking some times over the course of experiencing a chronic illness; due to the illness itself or the toll it takes on the rest of our energy, sleep, capacity to participate in our lives, tolerance off chronic pain, mood; and the strain it puts on our relationships as we can no longer the be the version of "us" that our loved ones were familiar with and may often expect us to still be able to be despite that we've become ill.
Chronic illness is exactly that: chronic IE permanent enduring long term; you may have periods where you "break down" but you have never and will never truly "break". Having a chronic illness teaches you the burden you are truly capable of carrying in this marathon of life. You may previously have considered yourself to be a person whom couldn't handle struggle, strife, obstacles, efforts, that require long time stamina.
Let it sink in that everyday your mere existence through life, regardless what you accomplish on a given day, is undeniable proof of exactly how much stamina you have in this life how much endurance. You should be proud of yourself for this skill.

2. Persistence- defined as firm or obstinate continuance in a course of action in spite of difficulty or opposition.
Now you may be thinking this is the same as endurance it is similar but with a very important distinction. Endurance is your capacity to keep carrying the burden of illness that has been cast upon you in your life without truly breaking Persistence is your enduring capacity to continue on with your lives and all that comprises that life despite the burden you carry. You still wake up each day striving to provide yourself the best quality of life and self possible regardless of being chronically ill. You do all you are cape able of doing, on a given day, to show up in the world and do your best and be the best version of yourself. Many people without chronic conditions don't bother trying to do their best or be their best. Often times when we spend so much time out of the game due to our illness we want to "make up for lost time or lost ground" and work extra hard when we are well enough to do so to give it our all in this life. Sometimes our mindset is so strong in this persistence to be and lead the best self and life possible arena that we overdue it and make ourselves sicker as a result. It is important overtime to learn to strike a balance where you do not miss that viable time but do not be so persistent that you will have a good life that you cost yourself time later by doing too much. In time you will learn that balance. In the meantime celebrate yourself for your super-powered effort for self growth and showing up in life.