People get mad when i stand up for myself

If your perception is that a lot of people are doing this a lot of the time, then it seems to me either you are indeed overly sensitive, or you're spending most of your time with immature people who don't like you much, don't respect you and are either unable to connect to you seriously or just don't want to do so.

Dickheads use the "only joking" ploy all the time. Trump is a high-profile example: he gives a speech to an arena of baying fools and says something outrageous, like encouraging police brutality, calling Democrats treasonous for remaining seated and silent during his State of the Union address, or how anyone who doesn't agree with him should be deported to North Korea, and then waves his minuscule mitts and says, "Only joking, folks!" But, of course, although his supporters are generally not all that smart, they understand what's going on: he's saying what he really thinks, then deflecting blame for any offence taken onto those who would be the victims of his malice.

It's sorta understandable when kids say something nasty and then trot out the "just kidding" or "no offence" defence. Children are trying to figure out how people work and how to fit in with whatever group they're in. Sometimes the method they use to do that is to push things to the limit and then back off. But adults who habitually do this shit are just assholes who are either attention-seeking or incapable of dealing with others in a respectful and sensible way.

Saying something rude to someone and then doubling down on the nastiness by saying they're to blame if they don't like what's been said is a form of aggression. If this is going on in any sort of relationship, it's a sign that the person being nasty is trying to keep an underling (or someone they want to be inferior) in their place. Try to imagine a member of Trump's cabinet saying to him, "Mr President, you're a lying, lazy tub of lard. Only joking, sir!" and imagine how he'd react. Now recall how he's not only insulted members of his cabinet in front of others behind closed doors, but during a press event at the White House he said that one of his cabinet members could be easily replaced, then followed that with "Only joking!"

If the people you consider friends aren't willing to treat you with respect and as an equal, then I'd suggest that you need to find some new friends.

Well, OP, it looks like you have some people that you need to cut out of your life. Some people are just really petty, and immature. It's okay to not want to spend time with people who act like stupid jerks. Hopefully, someday they will hurt the wrong person's feelings, and get their asses kicked, but it's not your job to give em that beat down, because you can be better than that.

I'm in a similar situation it's all people that knew me from years ago that are holding grudges and being dicks still and alot of them are just too narrow minded to even give a chance to the fact time changes a person like I used to be a very hot headed person my temper was at a short fuze but I got that controlled now. Some people are just to narrow minded to give you a chance to make them change your opinion on them. All that you have control of for sure is your self, you have control over whether you even stick around in that situation because you don't have to. You have control over how you react to it. Some people you just cant change

It's hard to say without knowing more details, but maybe you need to change who you hang around with. Your friends shouldn't make you feel this way.

Some people are super disrespectful. I think they became angered because, like you said, you 'brush it off' a lot, so they would be surprised when you stand up for yourself- maybe it's scary for them, so they are being defensive instead. It's definitely unfair though, they sound like ass biscuits :(

Honestly, they get mad because they know they are being pricks and you are confirming it for them by calling them on it.

I am terrible at this but the best thing to do is stop associating with them. I don't have the self discipline for that but maybe you do.

If you feel offended they should respect it and don't do it anymore

I have always tended to be easy going but when people I've helped (normally with money) start talking BS and expect me to fall for it they cross a line and I bloody well tell them so.