I think the thing to remember here is that we are complex human beings with complex thoughts and desires that we often don't understand ourselves. Add to that the fact that we inter-relate with unique and equally complex beings in a complete rats-nest of complex social structures ...
Is it any wonder that we do not fit into nice simple categories?
The words we use to describe ourselves, in fact the words used to describe many of the characteristics talked about here, are just words. They are a set of constructs we impose on the behaviours we see most often, and they do not describe all human behaviour and experience. They are akin to an imperfect map of the world, but that map is not the world.
I say that if you want to call yourself an asexual lesbian, then you are an asexual lesbian. If someone has a problem with how you describe yourself then that is their problem, not yours! These are words you choose to describe yourself, and these are the words that most closely align to your feelings. Such words can be a useful starting off point for a discussion but that is all they are. The definitions police should find another job.
I caught a wonderful line yesterday that made me think and that I will carry around for a while.
'I don't need you to understand me. I just need you to believe that I am having a human experience'
Yes, points up. All the boxes we use to describe ourselves are at best a jumping off point for conversation. I do hope the people questioning you were doing so in a respectfully curious way. (From the question, I doubt it though.) In the words of Ted Lasso "be curious, not judgemental."
I'd just add, a lot of asexual people I've personally had discussions with are not sex averse or sex repulsed (although they can be). They just don't seek it out or think about it or crave it. They don't have a strong sex drive.
This doesn't mean they can't enjoy sex. Many do. It may just be more planned or negotiated within the relationship. Or absent if that's what they prefer.
Be kind. Be curious.
Good day to all the asexual lesbians out there. *tips hat*