I'm looking for advice on how to start talking with my therapist about some difficult things that I've never spoken about before with anyone.

Now that I've made it through grad school (only my oral defense is left - yay!), I think I'm almost ready to try to work through some of my negative sexual experiences, which I've been ignoring for years, telling myself they're no big deal. They start with some memories from my childhood where I was acting in ways that in retrospect might be abnormal - I don't know for sure because early sexual exploration is not something that comes up very often in conversation, so I don't have anyone else's experiences to compare with my memories. Then I had some tough experiences as a teenager, with both friends and a boyfriend, and my mom calling me a slut; I've behaved promiscuously (and I use that term in the sense that I had a lot of drunken sexual encounters which left me feeling very empty afterwards, and which weren't decisions I made beforehand - more trying to fill a void than to have fun - not in a way meant to criticize people who have lots of fun sex with lots of different people), and I've felt a lot of shame about my promiscuous behaviour; and I've experienced sexual assault.

The therapist who I've seen throughout grad school is the best one I've been to, and he's much more open to exploring other kinds of therapy instead of or in addition to medication, but we haven't talked much about things other than what has directly affected my school life, namely depression and anxiety and work strategies. When I last saw him, I was doing well and on track to finishing my thesis, so I left without any definite plans to see him again (we've always worked on a 'when I think it's necessary' kind of schedule).


So, in spite of the great rapport that I feel with my therapist, I'm not how to go about broaching the subject of sexual trauma/shame/assault. I'm pretty damn scared about what it could mean for me to start talking about these things that I've experienced, and I was hoping there were some folks out there who could give me advice about discussing very difficult topics with a therapist. I'm not very good at opening myself up.

TL;DR: I'm looking for advice regarding how to start talking to my therapist about things that are really hard for me to talk about, and which I've never discussed before.