when all else fails, ya can draw direct inspiration from another character in media and try'n sorta play them out with your own twist. example: i really like doctor who, so one of the character i played's mannerisms/behaviour drew heavily from the doctor, even if they weren't a sci-fi timelord or whatever. i could give a bunch more examples but it's probably not necessary.

my advice would be to try and avoid the headspace of deliberately doing something opposed to what you'd ordinarily do. enslaving yourself to something that doesn't enthuse you is the best way to do a bad job and feel bad about it. that framework will make ya self-conscious. instead, however long it takes, try to formulate a character without those usual traits, that you really fall in love with independently of that fact. it may take time, and you may have to consume a bunch of media to find something that hooks you. something that makes you go: "i wanna play that!"

at the end of the day though, it might not be a seamless transition, yeah? playing a new character archetype is gonna take some gettin' used to. just remember that nobody even knows that you're unused to it, and there's no shame in it anyways.

First, I want to start by saying that there's nothing wrong with playing one type of character. RPing is a hobby, and if it's what you have the most fun with then it sounds like a thing worth doing!

That said, if you want to branch out, I think there's two good ways to do it. First, take the same kind of character and change it a little. Maybe they're an edgelord with a bright and sunny past and they're rude and combative for entirely different reasons. Maybe they were sheltered and were so used to getting everything they wanted that dealing with people who don't do that is hard, or maybe they're really insecure and afraid of being taken advantage of so they try really hard to push people away. Or maybe they have a dark and troubled past, but ended up being more optimistic and sensitive to the troubles of other people because of it and really want to protect people from what they went through.

The second is to think about what makes these kinds of characters so much fun for you. What interactions do you like? What themes do you like to explore? You can often get similar interactions or look at similar ideas with different types of characters if you plan them out that way. Like, I tend to like my rude and antagonistic characters because it's so easy to get reactions out of people and to make things happen in threads and I find that really difficult to do with super friendly characters that just want to be everyone's best friend. Thus, my nicer characters tend to have certain triggers or secrets that can bring out something similar.