YUUUUUUUP—a straight guy who likes getting fucked in the ass (and digs trans porn)—offers some support and perspective to a straight guy who's in a panic about getting fucked in the ass by a trans escort:
WSOWS, as a straight guy into pegging and trans-porn, I can assure you it's possible to be into these things and not be gay. I've never had sex with a transexual like you did, but I do like to be fucked in the ass with a strap on and regularly watch trans-porn and I am straight. I've never dated or had sex with a man, nor wanted to. Men just don't arouse me.
Why do I, a straight man, enjoy being anally penetrated and watching trans-porn? First, having stuff in my butt just feels good—it makes whatever else is happening feel that much better. Second, the idea of being the object that "gets fucked", instead of the person doing the fucking, is hot to me. I like the dynamic of that power switch, of becoming the one that gets penetrated. The turn on isn't the dick, it's the getting fucked part. When I'm getting fucked with a strap on it's not a substitute for a man fucking me with a dick, it's the fulfillment of my true fantasy: getting fucked by a woman.
I'm glad I didn't discover my "kink" at age 21, like you, long before I'd started reading Dan Savage, because I probably would have been as freaked out as you, worrying if liking things in my butt "made me gay". Luckily for me, I didn't discover my taste for anal penetration until late in my 20's after I'd been reading Dan Savage for several years (In fact, I discovered it because a SL question about pegging really turned me on ). Discovering the "kink" at that time, as an educated DS reader and with several years of evidence that I was straight, allowed me to just embrace and enjoy my "kink" without having to worry about "what it means".
My advice to you, WSOWS, is to stop worrying about being gay (and make sure your fear isn't stemming from homophobia) and try some pegging. If you liked getting fucked by a trans sex worker, I'm guessing you'll go nuts for getting fucked by a girlfriend you love wearing a strap on.
Glad I could help, YUUUUUUUP.