Pansexual but also scared

So ever since growing up I kinda always knew deep down I was pan. I remember kissing this girl when I was 6 and getting caught and it went on for a year. And I also would always say “I’m find dating a transgender person”. I’ve been in a relationship with my lesbian gf for 5 months now. And I’m fine with my sexuality although I haven’t fully come out yet to my mom. But anyways I’m scared that being pan that’ll I’ll get to close to them and start getting feelings for that person because it has happened before and I broke up with a guy because I just didn’t love him anymore. So I don’t know what to do?