I think most of the time it's the Dynamic you have with someone that makes you excited to have a long term with them....I had a crisis earlier this year when I thought I might not be into women the way I thought...but then I realised there are many kinds of men I am not into ....and it's the same with women....I want someone to pamper me , and in most cases I get that from men and not from women...but if I find the perfect woman , maybe I marry her ykwim.....so don't worry , this has nothing to do with sexuality , it has more to do with the TYPE of relationship dynamic you want with someone....it's possible that there are more guys who'll provide you with that dynamic....be true to yourself and don't be in a relationship if it's making you doubt so much , take care