Is it normal to envy others health?

I was born with a condition known as Cystic Hygroma which is a defect that causes abnormal growth/accumulation of cells that form clumps of matter in the body. These are in other words non-cancerous tumors. From birth till now I've had a total of 19 surgeries relating to this issue and the 3 most recent to newer problems such as scoliosis, and a spinal tumor which caused my legs to become immobile for 2 years. I fought back and regained full mobility of my legs and control of my body. Yet, my medical problems never go into submission for long. I'm not starting to experience new issues; that I may fear to be the precursor of a stroke, or aneurysm. I excluded a brain hemorrhage because I had a MRI of my brain and it came back as clean as a whistle. I've always had to deal with being mocked for walking with a limp, having uneven shoulders, or having a speech impediment. I would hate being touched because of the fear someone would feel my scar tissue from past surgeries, and they often did and showed a face of disgust. Nowadays being 20 years old. I've matured a lot, and now wear what I want and don't care if anyone notices anything odd, and if they notice something I always give them a honest answer. :D I do have a problem with envy. It's been more present now, because I'm trying to go to college which is difficult because of this new medical issue that I'm having. I look at my fellow students with envy. I just think of what could of been if nature wouldn't have made a mistake during my development. If I was just born 100% healthy. I sometimes look at others and feel anger and resentment which is a horrible thing to feel about someone. I know that anyone one can die at any time, and no one is guaranteed another millisecond of life, yet I willing to bet that if your born healthy in a 1st world country. You have a higher chance at a longer lifespan and happiness than someone like me who got a bad draw would. Nowadays I have very little motivation to do anything because I feel like another medical issue will just get in the way. I begin to think a lot about how futile and pointless existence is anyways. I mean what am I but a short lived organism clinging to its existence on a tiny world in a average galaxy among billions. I find it so frustrating! I know we must all die one day. Yet, I have so much I want to do in my life. Being dead at 20 is not one of them. I was basically dead for billions of years previously till now, and I'm not ready to step back into oblivion again. To think, I'm a member of the most intelligent species living on the only planet in our solar system that supports life. I am damn lucky to have been born to experience life as a human.