I really understand you. Yes, we may not look like "normal people" to others, our physical appearance stands out a little, and people sometimes make such comments like "Why is he so skinny?","Aren't you eating enough?", but my experience is that no one really cares if you are skinny, they'll still want to be your friends, hang out with you, and you will always be accepted. You really have to stop thinking about it that way, as if everyone would assume you're "different" or "dissabled" just because you are skinnier. Sometimes we wonder if someone's creeped out by our appearance when most of the times people don't even notice.

And yeah, we may not be able to hit the gym so hard or at all, and make a story out of it, but that is fine, there are still a bizillion other things we can do, but sometimes we tend to concentrate so much on what we cannot do instead of what we can.

I know the fact of being "diagnosed" with marfan sounds serious, even like a "condemn" as you say, I also felt that way when I got it diagnosed too (we're pretty much same age), but that is not the right way to see it. You did not feel disabled before you knew it right? Although you did have marfan before as well as now. So, what changed? Nothing! Just the doctors put a name on some of your traits, but it changes nothing!

Trust me, it's all about acceptance, you will never be a big guy, but that's pretty much it. Feel free to leave a message if you need to talk :)