One more time: You do not look feminine. Even if you did, the shaved look makes you look more mature and manly. I'm 19, and have always felt like a little kid, and saw myself as looking younger. So it surprises me when people mistake me for being 24.
Besides, you can try doing it gradually. And don't ask for permission, just let them know so they won't be in such a shock. Your family will get used to it, mine did.
Take note of Bald Hobbit -- he speaks the truth. You looking feminine is just BS and if we use a BS meter it will show:

in relation to looking feminine.
Breaking Bad makes baldness look so cool -- I bet HeadBlade sales skyrocketed when the series came on. I've seen it online somewhere dubbed into German.
Spüren Sie die Freiheit der ohne Haare
I have to agree with Bald Hobbit and I am younger than both of you I am in the 9th grade and have no hair whats so ever. The bald head will make you look more mature and manly listen to him he knows what he is talking about

Don't wait any longer or you will never do it. Do it now before you back out.
Welcome Kai,
Like frontier guy and all the others said...
...give it a try