Should I feel hurt or am I being selfish?

Need some advise or at least someone else perspective on my situation....

Three years ago I was diagnosed with Chronic Kidney disease. Over those three years my kidney functions decreased more and more and this past December I was diagnosed with End Stage Renal Failure. The doctors said that I would need a Kidney transplant and in the meantime will have to start dialysis treatments until I find a donor for the transplant. I was put on the national organ transplant list but was told that the wait could be anywhere between 2-6 years for a kidney. My sister and my best friend volunteered to be tested to see if they were a match to donate a kidney to me. My bff was tested but not a match. My sister was tested and she was a perfect match. After she found out she was a match she went ahead with all the other test to make sure she was healthy enough to be a donor. All test were coming out fine and we were both excited. She started testing back in February and we were looking at possibly having the transplant done by late March or early April if all went well. At first she was doing everything right away, getting all necessary test done but then things started to slow down. Then summer came and all of the sudden she didn't have time to proceed with the last phase of the process to become a donor. I would ask her how it was going and she will just say that she needs to schedule time to do the rest of the testing but she couldn't find the time. She tells me she doesn't have the time yet she took 2 weeks off of work to go on vacation and takes a day off here and there to go to water parks and amusement parks. On top of that she volunteered to help out a friend coordinate her wedding which takes alot of her time as well. How do you tell me you have no time yet you have time for all of these other things? I'm starting to believe she doesn't want to go ahead with the transplant anymore. I'm hurt because if that's the case she should just tell me instead of leaving me in limbo.