No you aren't the only straight mtf,lol. I personally find both genders attractive on a physical level, but I only have feelings for men romantically. I really could not see myself dating or being in a relationship with a woman. So, I consider myself straight for this reason, but some would argue against that. However, I do notice there is a higher trend of lesbianism in the transgender community. I suspect hormones and social conditioning may play an important role in this, but it doesn't really matter at the end of the day.
I can say I would date a ftm without any issue, but I don't know how they feel in general dating a mtf. It's all very confusing!!