None of us know how long we have on this earth, so make the most of life, while you have it. I've sadly had to say goodbye to far too many friends/family, who went well before their time ... life is too short to be miserable!
Don't worry about what others have, that you may not have.
What is important, is what YOU have, and making the most of your own situation.
We all go through good times and bad times.
When things aren't going well, the secret is to pick yourselves up, and dust yourselves off ... I know, I've been through bad times in the past, and then made an effort to change things for the better.
Try to surround yourselves with people you care about, and who care about you ... the ones who make you laugh and smile ... if they make you miserable, get rid of them!
You only get out of life what you put into it ... no one ever said it was going to be easy.
Life is what you make it.