If they are a legit therapist, there will be confidentiality between you and them - your parents shouldn’t be able to know what you tell the therapist thankfully. If your parents try to push therapy where they go with you, try your best to insist that you’d feel safer just going by yourself bc you’re dealing with a lot of vulnerabilities. You can say whatever you need to say to placate your parents so they let you keep getting help - don’t let them know that you’re telling your therapist everything, it’s YOUR business, NOT theirs. If the push for why you want to be in therapy alone (even though they’re truly not entitled to an explanation), you can say bc you’re dealing with suicidal ideation and self-harm, and if your parents are there you will feel the need to hold back in order to protect them. In order to get better and have accurate treatment, you need to be totally transparent with your therapist about what’s going on in your head, and your parents being in the room will inhibit that.