While I am sure it is futile to try to give you some perspective, I will join others in trying.
The first problem here is that you don't understand what it means to be "offended." You are viewing different levels of reaction as identical. For some reason, you are conditioned to believe having a passionate response to anything is a sign of weakness or failure. You think it's the responsibility of every able-minded citizen to disengage and not care about what's going on around them. This is probably because you have never been affected by the operations of an authority or a society that makes express attempts at eliminating you for how you were born or what you look like.
What you think it means to be offended is actually what it means to be insulted.
It is insulting to tell somebody to fuck off. It is insulting to place a crucifix in a jar of piss. It is insulting to take a selfie with an open casket. It is insulting to remove a silver cloche to reveal shit on a plate in a fancy restaurant. Being insulted is a virtue of sensibility - people react differently to an insulting stimulus based on all kinds of varying factors. This is why some people might think it's funny and some people might be distressed. Not everyone will react the same way to somebody streaking at a sporting event. Some might turn their nose in disgust and others might cheer and clap.
But there is lots of room in society for insult and injury and it's all right that not everyone feels the same way about these things. While the appropriateness of these gestures can be debated and discussed, they are not an act of hatred or degradation. Society is not set back or fractured because somebody said something rude or did something abnormal.
But some insults are greater and have stronger impacts than saying "you're a really terrible athlete, you should quit the team." These things can hurt someone's feelings, and they might make you an asshole for saying them, but they do not normalize the idea that other human beings are lesser than you. They do not encourage the thought that you should rape and kill at your leisure and discretion. They do not promote the idea that people need to stay in their place or face brutal and unforgiving consequences.
They are not inherent acts of hatred. They are not intended to be acts of violence. Other things are.
Calling somebody a fucking faggot is not the same as telling somebody to fuck off. Faggot has killed people. It has made people hate themselves and live in shame. It has torn apart families and castrated geniuses and cost people their livelihoods. It made people afraid to ask for help when they've been abused, it stopped them from getting medicine that might save their lives, it drove people underground and away from society for wanting to indulge in their basic human impulses. People who use this word don't want to offend you, they want to humiliate you. They want you to feel lesser and smaller and meaningless. They want you to not exist, to have never existed, and to never exist again. They want you fucking gone and they relish in the opportunity to advance that thought.
Does that mean every single use of the word faggot or nigger is motivated by this? No, not necessarily. But it means you should be very, very considerate in how you use these words. Because treating them like they mean nothing is an absolute failure in compassion. It says "what has happened to you doesn't matter." It says "your history is not important." It says "my joke is more important than your life."
Flags of the Confederacy and Kekistan and other white supremacist bull shit are offensive because they are constructs of exclusion. They are totems that say "I hate you and think your suffering is hilarious." They are explicitly designed to frighten, disparage, and disenfranchise other human beings. These things are not just insulting. They are not something you can shake off or ignore. These are assaults on the integrity of your existence. The implication is that there is none.
Hate speech has two goals:
1. Normalize and promote ideologies based on hateful division
2. Frighten people affected by those politics into submission
So, to combat them, you have one singular option: to react strongly and negatively. Because that's what people flying these flags don't want you to do. When you do, they laugh. They try to delegitimize your opposition as trite hysteria. They'll call you triggered, they'll call you SJWs, they'll laugh at you and make subreddits about raping and killing you because you're such worthless fucking trash. These are their attempts at making you stop - at silencing your opposition. They want you to fall in line with them or to enable them with your apathy. It doesn't matter which one, they win either way.
They are not just words or just symbols. People are not "giving them power," they are designed to be powerful. They are tools of attempted authority. They incite hostile response because that is how they are intended to work. They attempt to victimize as many people as possible in pursuit of ethnic and social dominance. And when you don't react to them, you reinforce them. When you don't take them seriously, they gain ground. When you give them a pass, they become justified and vindicated and validated and they cross more lines and make bolder plays for power.
When you say people shouldn't be getting upset over something that has historically ended the lives of people just like their friend and families, you're wrong.
You're selfish and you're wrong.
Afterthought edit: I don't take my use of the language above lightly and I hope people will forgive its use in this context - it is meant to demonstrate the severity of the verbiage. I am uncomfortable still by even this use of the vocabulary and hope my intentions are plain.