It’s a slow and difficult process, but yes. There are certain personality disorders that can be provably put into “remission,” and if people with conditions that severe can change their personalities, anyone can.

You have to learn how you’ve been conditioned to think and feel the way you do, and get a lot of self-discipline re: stopping to notice your feelings, figure out why they’re arising, think through the consequences of acting on them, and choosing a better way.

I hate to use terms like this since they’re so often the territory of conspiracy nutjobs, but you’re basically deprogramming yourself. For example, a sensitive person who’s been exposed to a lot of bullying might have learned some pretty intense defensive reaction, so you’d have to stop every time you think “what did he mean by that?” and think of why that’s your first reaction, then choose to believe the best possible meaning even though your feelings scream at you not to. And you’d maybe keep a journal to remind yourself of all the times you were right to assume the best, since a defensive mind discards the positive and overemphasizes the negative.

This sort of thing is best accomplished with the aid of a mental health professional, but there are workbooks you can get if that’s out of cost/feasibility reach for you. You’d need to know your deal to know which ones to focus on.