When I first started coming out as trans, and was introduced to trans community, one of the things I learned was that many trans people's sexuality changes with transition. That anecdotal information is backed up by science.
Several studies have shown that changes in sexuality are relatively common among trans people. For some (this is true of me), it's an expansion of attraction - some trans folks become bi- or pan-sexual. And others switch attraction entirely - switch from being attracted almost exclusively to one gender to another one.
There are lots of theories as to why this happens, but that's not what I want to dive into in this post. First, I want to let you know that if you are experiencing this, you are far from alone. You have a lot of company.
Second, your experience is valid, whatever it is. For a long time, trans people had to be attracted to people of the opposite gender, or else they weren't considered candidates for medical transition. That was in the days when gender and sexuality were considered one thing, not as two complex, somewhat independent things. So if you were a trans man, attracted to men, that wasn't considered a valid choice. Luckily, that's not really true anymore, but it still lingers in some people's minds.
And for many trans folks whose attraction doesn't change, your perceived sexuality can. You might go from being perceived as a gay/lesbian/queer, to being perceived as straight. Or the reverse. And this change can sometimes feel like a challenge.
Remember to be gentle with yourself with these changes. They might feel overwhelming at times, and a lot to handle. Be slow with yourself, allow yourself space to explore these new attractions, and what they might mean to you.