I took time to reread your post more than once... here is what jumped out at me...

you and this girl were sexually active on church property (evidence you stated they caught you kissing, holding hands and heavy petting, they would not have caught you if you were not doing this in/ on church property. right? if you were not doing this on church property then the church (pastor/ reverend ...) would not have caught you.)

the church talked with you about this acting out on church property.

the church after trying to discuss the problem told you that though you would not be considered a member of that church you .... could.... continue to attending their church services if you follow their dress code.

you refused to follow the church dress code and code of behavior.

none of that says you got excommunicated for being a lesbian.

lets put it in another situation...

a high school and their dress code and their no smoking code. ok if you get caught misbehaving and not following a schools dress code and a schools code of conduct a student gets expelled. its not because they are a lesbian, its because they broke the rules.

another example going to the mall or shopping

stores have a dress code people have to wear shirts and shoes. and they have a code of conduct no stealing, no damaging property, no sexually explicit behavior. if a shopper goes to this store with out their shirt, shoes or attempts to use the dressing rooms for sex they are asked to leave and if their behavior doesnt change they are told they can never enter the store...

my point...

the church has a right to set their own rules of conduct and dress code and a church has a right to work with the church member to try and work out the problem but if the member refuses to follow the rules then they are told they are no longer welcome.

its just the way it is in churches, schools, stores and other public businesses.

my suggestion is if you want to be a member of this church then you may have to make some hard decisions like not behaving in sexual manner in church and follow the churches dress code while on their property and attending their church.

maybe this will help going to church is what a couple hours out of 166 hours a week. that means you have 160--162 hours a week where you can meet your friend a place that it is acceptable to kiss, hold hands and heavy petting like her home, your home, a hotel, a motel and other non public places where there are no laws about public sexual acts and crimes.