I think the best advice I ever got before is "you cannot give what you don't have" and "don't expect what you can't give". Life is a simple and less entangled as that.
I cannot give to the world what I don't have. If the world needs humanity, compassion and love, I cannot be part of that if I do not love myself, if I'm full of resent. Healing the world starts from healing ourselves and being whole.
We should not put our expectations on people else we would be disappointed. If you don't place high priority and don't do so much for people, you cannot get any of that. This life is give and take but to live peacefully without disappointment or dissatisfaction, even when you give, do not expect so much in return. Do it for your peace of mind.