I don't have experience with low testosterone in the sense that the other responders have, but I actually suspect that low testosterone levels cannot change your personality to the degree that you're describing. Testosterone affects physical and some mood characteristics, but definitely not a person's personality. I am a trans person who was assigned female at birth and my body naturally produces estrogen, and for the past few months I've been taking testosterone to alter my body. In generally it has made me a happier and more active person, but it has definitely not changed my hobbies or lifestyle, and it cannot change your "mental gender". I would caution you that testosterone replacement therapy may not give you the results you desire, and it's worth examining the feelings you're having now and where they originate from. There's absolutely nothing wrong with being not-manly, unless it's something you don't want. Good luck.