Have you had a history of being forcefully hospitalized?

In general, they do that for people who seem to be on the verge of committing serious injury to themselves or others (have detailed plans) or have a history of that. To merely mention bad or angry thoughts does not mean a therapist will necessarily do that.

I know this is a common concern for many people, who powerless as they are in dealing with mental health issues, fear losing whatever little power they do have, by the person who is supposed to help empower them! So I think one of the things you could do is research your therapist and make sure this person is licensed and well trained. Cause first step is get a competent helper. Then secondly, straight up, ask them, tell them this is a concern you have and under what circumstances they would forcefully hospitalize you. You can also ask them what hospitalization would entail and what would they do exactly. Trust me, they've had patients ask them these kinds of questions, they're ready to answer them.

So I think your concerns are legit but I just hope they don't stop you from looking to get help that can help you feeling less depressed. Good luck.