It's very common to hold back in therapy. Why would it be easy to share all of our most destructive, embarrassing, shameful, confusing, upsetting issues with someone? Hopefully though, as the therapy progresses, it gets a little bit easier every week until you do feel safe enough to share a little bit more. If you're worried you will hurt yourself, if it's going beyond thinking about it, I encourage you to push yourself a little bit: print this out or email it to your therapist, or call a crisis line, or do whatever it takes to be safe. If it's intrusive thoughts, but you're not going to act on them, well, you've already been toughing it out a while, which I'm sorry for, but sharing it here is a great step, and I trust that if you're with a good therapist, you'll get to the point where you see it is safe to trust them to help you and not judge you since their sole purpose is to be your partner in making a good life for yourself.