Labeling of sexuality has started to be divided into two spectrums (1) sexual preference and (2) relationship/emotional preference. There is also a third dimension that describes how you get aroused. For example, demisexuals can only be aroused by people that they have an emotional attraction to. In your case, you can get aroused by women, but not as easily as with men. Perhaps if you were in a relationship with a woman this would be easier. Or maybe not.
It sounds like you are heteroromantic, hence why you label yourself as straight.
I am somewhat similar. I've struggled with labeling myself. My attraction to men is only with a particular fetish (not general sex and not a relationship and what arouses me is a particular act, not the guy himself), but it's a very intense fetish that consumes a lot of energy. But I am fascinated by women's bodies and think about them a lot, whereas I am not fascinated by men's bodies outside the fetish. Neither sex really arouses me all that much, but I can get an erection and have sex with women but it takes time. With the fetish with men, it's very quick.
The thing is, sex is more pleasurable when it takes a little while, so maybe this is a good thing (?).
I think to figure it out, you need to try to experiment. Or, if you're happy being with women over men and prefer that, then you do you.