<human>: Can you summarize the given text in a few sentences?

It has been almost two months since my ex-boyfriend and I broke up and I feel so terrible about what I just did. Long story short, I got on my personal computer, which I haven't used in a couple months, and when I went to sign in to my Facebook page it auto logged in to my ex-boyfriends page. I guess it saved his password when he used my computer a few months ago. I'm not sure. 

I know I should have signed out right away, but I didn't. I was curious. And angry. And confused. He had been talking to some other girl on Facebook messenger. Even though the conversation was very platonic, I made a very poor decision and started blocking girls he had been talking with in the last few weeks. It was probably around 2 or 3 people. I just remember being upset and blocking a few people - then logged out. Ugh... I feel terrible for doing this and I'm sincerely sorry for causing trouble, but I'm also worried he might know. And I'm worried he might know it was me. 

Should I tell him what I've done or just forget about it completely? If he knows then it's likely for him to suspect me. What would you have done if you were in my shoes? What should I do now?
<bot>: My ex-boyfriend left his Facebook page open on my personal computer, so I started blocking a few girls he had been talking to over the last few weeks. Now I feel awful and think I should tell him.