Telling someone you're new to dating about having EM?

So long story short So I've started seeing someone new. My ex knew all my weird food allergies, how I can't use scented anything, my weird "conditions", oh of course that "I sleep too much", and for the grand finale my amazing EM! So now the new guy. I've had the courage to start seeing someone else since my ex left. We talk all the time but not so much on like deep personal stuff. During s conversation tonight about magnesium because his muscles were hurting, I said I take magnesium to help with my nerve disorder as well. He asks what kind of nerve disorder I have and I briefly mention EM. Ok so this guy is Mr. Havasu, beach ready, hiking all that fun stuff that I tottally circled my life happiness around with my kids. Now, he'll I get excited if I can make it through the entire grocery store trip without having to take off my sandals...

So I guess what I'm asking is, how do you explain this to someone. You come at them straight "hey I'm sorry I can't hit havasu this season but if love to sit all day in a very cold hotel room"....

And I supposed that goes for any kind of chronic illness. How do you explain this to someone??? Like without them running for the nearest border??

For me this sums it up (from How to get on with your dating life when you have a chronic illness):

There’s no perfect time to tell them about your disease

One of the biggest challenges about dating when you have a chronic illness is trying to figure out when to tell the person you’re dating about your disease. Some people will tell you that you have to wait until things are more serious between you two before the big reveal about your illness. Other people will tell you it’s absolutely mandatory to inform them up front, because they should understand that dating you might have some challenges so they can decide if those challenges outweigh the awesome privilege of getting to be with you. I say there is no exact science to it. It’s up to you when you tell the person you are dating that you have an illness. For me it varied depending on the person. I told one guy the night of our first date. I waited about a month to tell someone else. My current boyfriend knew I was sick long before we started dating, so I didn’t even have to bring it up during the “get to know you” stage. Just go with the flow, and do what feels right. Remember, whether you choose to tell them right away, or whether you wait to see if the person is more right for you, there is no wrong time to talk about your illness. If you are dating someone and you feel like you cannot tell them that you’re sick because you worry they would stop liking you, maybe they just aren’t the right person for you. You deserve someone you can be yourself with!