Nobody around me understands

So since my daughters seizures have been a big part of my life, I have discovered that alot of my friends just don't get it. I know that if you're not experiencing it you will never know, but when I try to vent or just want to cry to someone, that's all I want to do. When all of this first happened I kept everything in and handled it all on my own, until I had a huge melt down in the middle of the hospital and a complete stranger sat down next to me on the floor and asked what was wrong. I completely unloaded on this lady about everything that was going on and she just sat there and listened. She never said a word the entire time, until I was done. When she looked at me and said "there now, don't you feel better?" Then she stood up and helped me up, gave me a hug and told me to always find away to talk about it. She then walked off. Anyway so since than I have tried talking to some of my friends about it and have been met with support from a very select few, and other just seem to change the subject to something else, or even tell me "well I don't know it's just something you have to deal with". Ugh I know that I am dealing with it, I hae been dealing with, I will never stop dealing with it, she is my baby, I will do whatever I have to do.  Why can't some people just be there for me, all I have ever done is helped my friends with everything, and now when it has come full circle and I need support they can't do it.