Hi! I sort of came back here after seeing this post and a couple comments before it and just wanted to kind of speak to a bit of this.
“Was bi sexual who later became pan sexual after learning about the term”
I do not necessarily understand/agree with the way this is phrased. You didn’t become pansexual by learning about the term, you just discovered a definition that was personally more accurate to your understanding of your sexuality. Which is awesome! Like, I wouldn’t say I became bisexual by learning about the definition, ie I have always been attracted to more than one gender identity.
Shiri Eisner writes a book, “Bi: Notes for a Bisexual Revolution“ that talks a great deal about how we must have intersectionality, especially between Bi and Trans people. It reflects a lot of my disdain for people who claim to be bi but are trans-exclusionists. I recommend this book to a lot of queer friends, especially those who are bi/pan, because we should also have solidarity, celebrating our similarities and differences. Posting a link to an excerpt here: https://radicalbi.wordpress.com/2011/02/22/words-binary-and-biphobia-or-why-bi-is-binary-but-ftm-is-not/
As far as the acronym/etc, I refer to the “third chair” argument near the end of the link posted above. I’m familiar with LGBTQIA+, and I think TPAN is fantastic to use when referring to situations experienced by members of those communities, but not others within the queer community.
I support our trans comrades and I support you as well, my pan friend. ☭