Plus what if my therapist thinks I'm a terrible person for not being rainbows and glitter yay?

If your therapist judges you like that, he or she is a crap therapist. From what I understand, there are a lot of them about nowadays. I am so sorry if that's the kind of therapist you have.

Then again, in therapy, it's always been customary for clients to feel bashful and reluctant about divulging certain things for fear of the judgment they assume they will get in return. Sometimes/often this comes from clients believing that they not only can read other people's minds (including their therapists' minds), but they can do so in advance: I can't reveal my true thoughts or feelings to this person coz I already know what she or he will think and say, and that she or he will condemn and ostracize me. So why bother bringing the topic up at all?

A good therapist won't judge you, and should help you see that in fact none of us know ahead of time how others will react to our disclosures. What's more, it's perfectly possible - or it used to be - for humans to disapprove of what others believe and have done - and sometimes continue to do - but not write them off as "terrible people" overall. As Aleksandr Solzhenitsyn said in "The Gulag Archipelago":

“The line separating good and evil passes not through states, nor between classes, nor between political parties either – but right through every human heart…even within hearts overwhelmed by evil, one small bridgehead of good is retained. And even in the best of all hearts, there remains…an uprooted small corner of evil."

Also, what if your therapist did think you're "a terrible person for not being rainbows and glitter yay"? What is she or he going to do to you?

One of the most liberating moments in my life was when I realized in early adulthood that if I spoke up and stood my ground at work, in the classroom, or in public forums, people might say mean things about me and give me the cold shoulder, but it was highly unlikely that anyone in most work and social settings would smack me in the face or make me stand in the corner with the contents of a trash can dumped on my head the way the nuns in the RC convent school I attended as a child often did to us kids. Around the same time, I realized that never again would I have to put up with anyone in my intimate or family sphere hitting me with a paddle, punching me in the face, washing my mouth out with soap, sending me to bed without dinner, cutting off my allowance, etc - coz I was no longer powerless the way I had been as a child and teen.

OP, you're coming out of an emotionally abusive relationship. You say your husband rejected you; I imagine he probably did so in cruel ways. It's completely normal to assume and fear that the whole world is emotionally abusive and rejecting just like your husband was. And now your friend has discombobulated you by her decision to go trans.

I wish you the best. There are lots of people in the world who are not rigid gender ideologues. I hope, and trust, you will find some. Take care.