I agree with whats been said so far. Some new friends and the Golden Rule.
Its really disrespectful when people just barely acknowledges you.

But you also really remind me of a women i once knew. She was almost saying exactly what your saying, and i really believe she was trying her very best to be kind and friendly to everyone.
Sadly i think her best was just too good. She was so intense about being good that it come off as almost strange. People just noticed it right away. She was really "trying too hard".
When she was little she lost her mom and i believe thats why she was trying desperately to make everyone around her happy so they wouldn't leave her.

The point is, becours she was trying so hard, it worked against her. And when she calmed down and tried not reading too much into normal everyday situations, people around her started enjoying her company and showed her more respect.

I dont know if any of this would apply to you. But its something to consider at least
And ofc theres nothing wrong with being friendly! The world could always use more of that. And maybe you are just surrounding yourself with very self centered people. So time to find some new people. Maybe pursue some dream or hobby and make friends through that. Sharing a strong fondness of something is a great way to make friends since it tends to happen organically.

Best of luck!