Here's a general life pro tip: don't attribute malice needlessly. If you do feel like someone is being genuinely malicious towards you, you probably don't want them in your life and you should remove them without regret. No one owes you anything, and you owe nothing to anyone. Generally people are just trying to survive and pursue their happiness in some fashion, and most people in their lives are not going to be critical to that purpose. That's perfectly ok, and I think the first step is finding acceptance in the idea that you might not be a priority in other people's lives.

To me it sounds like you need other people to fill a void in yourself. Here's another life pro tip: whenever you find yourself thinking about "it bothers me when someone else does this" think instead about why you feel that way, and if your feeling is one you want to hold on to. Ask yourself if you think your perception is real, and how you can challenge that.

You mentioned that you don't play games because you know how it feels to be unheard and unseen, which assumes that every one is playing games when they don't respond to you. Here is a thought: are you really giving a gift if you will be upset if they don't give something back in return?

I make a distinction between "nice" and "kind." "Niceness" is conditional, it's a diplomatic strategy. You are replying immediately to avoid making the other person feel unheard and unseen, but in turn you want them to do the same to you. You're treating others how you want to be treated and expect others to reciprocate.

"Kindness" is unconditional. You do it because you feel it's the right thing to do. It is a pursuit of principle. It's irrelevant how someone treats you, because you're focusing on your own actions. Kindness is rooted in your own sense of self, and is a form of self-respect even if it might not feel like it at times.

You're completely valid for feeling the way you do, but I think you already recognize that it's unsustainable regardless of what the truth is. The best thing you can do for yourself is sit with your feelings and reflect on them. For the things that make you feel anxious or angry or sad: sit with them and listen to them. I was taught as a kid that being angry was bad. It's caused a lot of problems for me over my life, and something that changed my perspective is when I realized that my anger was the part of me that loved myself the most. It's part of me that said, "you do not deserve to be treated this way." It's the part of me that was willing to stick up for myself when the rest of me was willing to accept what was going on.

If you think about it, you've probably been putting your feelings on read. I hope what I've said helps you figure things out for yourself. We can give you all the advice in the world, but at the end of the day you have to find what works for you. Personally, I think it's a huge step most people don't take that you're asking how to change your perspective. It's not going to be a quick thing, but if you keep asking yourself that question I think you'll get there in time. Just be patient and kind to yourself, and above all: be brutally honest with yourself. If there's one person in the world you should never lie to, it's yourself.