Sorry I made you cry. (Well, a little.)
Now, now. No shouting necessary. LOL!
I wanted a Snape who survived, but at a cost. The poor man, how we love to torture him! But yes, at the end, he had to be out of pain and... Well, look at it this way. Portrait!Snape is alive and well. And will make Harry's life as difficult as he can, all the while teaching Albus Severus a lot of things his father would prefer he not know.