If you go to the market right now and make an announcement that you want to share free money for everyone, you will see crowd gather around and queue up in your front. Go to another public place and announce that you are sick or in a serious problem, tell them you need money to treat yourself or solve your problem, watch how people will ignore you like you never exist.
This is a big life lesson that you have to learn from. People don't just abandoned you for nothing. Just because your family does not ask after you or reach out to you, it does not mean they have neglected you. Your friends are not evil just because they refused to be around when you need them the most.
The sad truth is that the problem is you. If you don't give, you will never receive. And even if you give, don't expect too much from others. When you do not give out something that benefits others, people will not want to give back something that benefits you either. The more you give, the more you receive. You can still give and not receive. But it is better to still give, because that is the only way you can get the chance to receive back from others who appreciate what you do for them.
Whenever you feel abandoned, don't start blaming others, check your behavior and attitude towards others first. It is human nature for people to always run towards givers, and run away from those who only take. Be a giver not just a taker.