Don't be too hard on yourself Wendy, there's really no proper way to handle a situation like this. How many times in life are we told we have an incurable and sometimes fatal illness? Hopefully never, but when it happens, it's such a significant life event, that there is nothing you can do to prepare for it. There's no instruction manual, and there's no right or wrong way to handle it.
As far as not having a partner, that can be both bad and good. I did have a partner, my longtime girlfriend (6yrs) and soon to be wife could not handle my diagnosis and left only a month before we were to be married. I thought I could bounce things off of her, and have someone to talk to, but it wasn't to be. I often think that I would have been much better off not having anyone in my life. The diagnosis was hard enough, and the added stress of the sudden breakup almost sent me over the edge.
You may meet someone to share your life with, and you can be up front with them about your situation so they know what they are getting into-not a bad thing.
There are indeed people who care, and understand. I've surrounded myself with people who understand both in my daily life as well as here at this site. They all make such a positive difference in my life. I would tell you to be brave, but it sounds to me like you already are. Keep that positive outlook you have going, it's a very good thing to have on your side.