What have you tried, and what was your experience with that?

You can start almost anywhere, but one thing that comes to mind is to do some journalling where you separate the bullying part of you from the kind side of you, and then write out their conversations. Here’s the ruled for that: the kind side of you is never unkind. The bullying side of you isn’t a bad person, it is more like a kid that wants something but doesn’t know how to ask for it properly so it rages and sneers. The idea is to figure out what it wants, but often the answer is just “to be heard” so the journalling itself is helpful.

Here’s some more on how you can use this technique: http://www.fluentself.com/blog/personal/the-negotiator-the-monster-and-the-scribe/