Legal Advice Anyone?

Hello everyone, I'm looking for advice regarding violation of privacy. My ex boyfriend somehow logged into my email. He said he reset his phone and it automatically logged into my account as well as his (we used to live together and share a WiFi network). He of course went through my emails and found a few pictures of me in my underwear that I had sent to myself when switching phones. They're not super revealing but I would definitely not want people to see them anyway, especially my professors and people I go to college with. He hasn't said anything yet, but I'm afraid he might threaten to post them somewhere, because that's the kind of person he is. I tried doing some research but legal stuff is very convoluted, so all I got out of it is that the way he got the pictures was illegal and if he were to post them somewhere that would be illegal too. In all honesty I don't have the funds to take legal actions even if he did something like that. Is there anything I can do to protect myself? I'm pursuing a career in a field where having inappropriate pictures of me on the Internet would be very fround upon. Any advice would be greatly appreciated!