Could anyone help me here?

So here's my current situation. My boyfriend and I, let's call him Harry; Harry and I had been for a little over a year now until I choose to end it on Sunday. I immediately regretted what I had done because I'm still madly in love with him, I think I handled the situation poorly and now he absolutely hates me. Now let me explain why I choose to break up with him. I had a gaia account that I quit a little after we started dating, my brother has one as well and I finally gave him the okay to take all my stuff on Sunday. So to make things easier for him he asked if he could use my computer and I agreed to let him. Now prior to letting him use my computer I checked my email to see if my grandpa had emailed me back, I left the tab up when I gave him the computer. So later on Harry came over and I wanted to show him something online. He saw the gaia tabs up and apparently saw a messaging tab, when I checked my history later on there was no messaging going on when my brother was on my computer. On top of that he saw that I had googled facebook search which upset him as well because we both deleted our facebooks. Now the reason I was on facebook is because my friend told me this really creepy kid was stalking her and I was curious about his profile. As you all know you can't use facebook search unless you are logged in so I used my brother's fake facebook to login. He saw that the email was saved on my computer. So after he left my house he texted me and started accusing me of secretly going on both websites and talking to people, which is as you now know completely untrue. Now after I explained why I was on those websites he refused to believe me and continued to accuse me of his original accusations. Now this wasn't the first time that he had falsely accused me, another example is that he is frequently accusing me of cheating on him. Once he was in the area and he called, I missed his call because I was in the kitchen and I had left my phone in the living room. He freaked out and told me someone else was over and that I was cheating on him. So basically the most recent incident was the last straw, I told him if he couldn't believe me then we couldn't be together because trust is essential to a healthy relationship. He refused to believe me so I ended our relationship. I immediately regretted my discussion and after trying to reason with him to at least come over and talk to me one last time, he refused to see me. So how can I get him back, what should I do?