People are going to People
When I was able to do my own therapy, the therapist I had gave me the most simplistic yet fundamental piece of advice. She said "Raymond, you cannot control or predict the actions of others, you only have control over you and your actions." I took that and made it my own meaning "People are going to People".
I think the reason that this resonated with me so much was I had the belief that people were going to treat me like I treat them. The issue with that is, I cannot control how others act or respond to how I treat them. People are going to do them. The most important thing that you can do is show up authentic as yourself. Show respect and do the best that you can.
There are very kind and caring people in the world, but they may not live up to your expectations. Try and have realistic expectations of others knowing that, they will do them. People are going to do them. So, you do you with honesty, integrity, and to the best of your ability. That's the only thing that you can control.