Basically poker is a fight for the blinds, and when we bet, we are in a position, where we expect to make money (or win chips in tournaments), because otherwise we would not be betting. However when we get raised, now we are in a position, where we expect to lose money except those few times, where we are at the absolute top of our range.
So basically someone is fighting back at us, and its not a good situation for us. So its easy to get emotional about it, but its also very important not to. After all raising is part of the game. We do it to other people, so of course they are also allowed to do it to us. Its not like, its some kind of personal insult to get raised.
Sometimes we might feel, that other players are out of line against us, and maybe they are. But even then it is important to be analytical about it and react in a rational way. If someone raise to much, we can look to widen our calling range and throw in some more re-raises, but if we are at the bottom end of our range, we still need to fold.
If for instance we open K9o from CO and get 3-bet by a very aggressive player in the small blind seat, now is not the time to fight back at him with a 4-bet. We just need to let it go, because if our 4-bet get action, we are completely toast, and we have a lot of other hands, that are better to turn into bluffs. Hands like A2s-A5s for instance. Instead a reasonable adjustment is to nit up a bit and not open hands like K9o, so that next time he 3-bet us, we are less likely to have a hand, that has to fold.