<human>: Can you condense the text into a few key points?

Ill give a full but quick story.
(Posted earlier but problem with the post)

New boyfriend(M22) and I(F19) have been going out for a little over 2 months. Things have been great, we get along amazingly and I'm totally falling for him. He moved out into a friends old family home when we first started dating. Well, his ex, whom I went to middle and high school with lives across the street. I trust him completely. They were only together for a short time but the jealousy in me just can't stand it. We had a small get together about a month ago and she came... She was a huge bitch me to the whole night for being with a guy she dumped... She was over again last night, we both didn't see her, just heard her voice... (His roommate and her are best friends...) This instantly put me in a bad mood. I'm not sure why I feel so strongly about this. I truly do trust him, she treated him like shit and I know he wouldn't go back to her or anything, but it seriously bugs me, and I dont want this to ruin our relationship.. Is there a way I can just get over this because I want too. Any input reddit? Thanks!!
<bot>: My boyfriends ex lives across the street from him... We see/hear about her often. I'm trying to get over it.