Hi, !
In addition to the great resources Alene shared, I wanted to dig a little deeper into your questions and share some info with you. Apologies in advance if it feels like information overload, but you asked some really GOOD questions and they can't all be addressed in one comment. I do hope other community members will see your post and chime in to answer your questions.
I know Alene touched on the subject of diets and MS and I just wanted to reiterate that some diets have worked very well for our members while others haven't seen much in the way of improvements. Much like MS presents differently in each person and people respond differently to conventional treatments (medication), it stands to reason that even natural/nutritional treatments won't work the same from one person to another. That said, a health diet low in processed foods and junk is always a good idea. And some individuals have had luck with the Wahl's protocol. Here's some helpful basic information on the common diets you will read in MS communities -- https://multiplesclerosis.net/living-with-ms/diet-nutrition-suggestions. There are also some great comments at the end of the piece from other community members.
As far as MS triggers, well, that also varies widely from person to person. Some people are triggered by heat, others by cold. Some are triggered by stress. Here's a compilation of our communities top triggers -- https://multiplesclerosis.net/living-with-ms/top-common-triggers. It may take some trial and error you to pinpoint your own triggers.
When it comes to other health conditions, many people do deal with more than one health condition, but that's not always the case. Being diagnosed with one autoimmune condition like MS, you have increased odds of being diagnosed with another autoimmune condition (Rheumatoid Arthritis, Lupus, etc). And, as we age, we are more likely to be diagnosed with conditions like osteoarthritis, type 2 diabetes, hypertension, etc.
I know this isn't a full answering of all your questions, but I hope this gives you a good place to start!
Best, Erin, MultipleSclerosis.net Team Member.