I'm sorry you went through all that, that's rough. I hope your time in here helps you find some answers. My personal opinion, no professional by any means, no, watching same-sex porn does not mean you're lesbian. It could be an indicator, but I think you'd have to have a lot more indicators popping up before being more sure. Perhaps, as Skeezy suggested, you're a little closer on the spectrum to being bi than you might have thought. Or it could be as simple as you mused earlier: good straight porn is hard to find.

A little of my background, I'm a porn addict trying to kick my addiction, and find ways to manage my sexual needs that don't harm my relationship. Years and years ago when I first started watching porn, I watched lesbian porn almost exclusively for similar reasons to what you shared: the men are frequently boorish and unattractive, and their acting is usually atrocious and degrading towards the women (speaking of that spectrum, apparently I don't enjoy porn with unattractive men in it, so there's that). However, I had a much easier time finding lesbian porn where the women were both attractive, who didn't treat each other poorly, and their acting was much more believable. I slowly started finding more acceptable straight porn as time progressed, and then my measure of "acceptable" slowly became laxer as my addiction worsened and I needed different mediums of stimulation, but lesbian porn remained a solid go-to when I needed my fix. So I get what you're saying about straight porn. A lot of it just sucks.

That said, I'm curious. Are there particular times you feel the desire to view this porn, or are there things that trigger the desire? Is it on a frequent basis or just once in a while? And forgive me if this question is too personal, but do you use it as a masturbation aid or are the two typically exclusive? The reason I'm asking all this is perhaps there's some clues to be found in the context. Maybe the desire to view is triggered by a person you know, or by seeing a woman you find attractive. It could be just something you find excites you right now, something fresh and exciting to stimulate you, or perhaps it's been more pervasive than that in your life, more consistent. Perhaps there's something else going on, and the context of your consumption will reveal that thing. If nothing else, these are things you can ponder and perhaps bring up with your therapist the next time you see them. Have you discussed your concerns around your porn consumption with them?