I'm 21 and I'm 5'2" with braces, meaning some people can easily mistake me for a 12-year-old. It's not true that people regard you more as a child than an adult when you're only short; especially once they get to know you. Why on Earth should you care if a stranger thinks you're a little girl? You don't know them, so why should their view of you matter. When you walk past a tramp/bum on the street and they ask for the "little girl" to spare some change, do you feel you have to walk back to them in high heels with make-up on and your hair done to prove to this homeless person that you are really an adult?
As for being cute rather than sexy, what about the millions of men out there who idolise Salma Hayek, Christina Aguilera, Kylie Minogue, Eva Longoria and so forth as sex symbols? They're all 5'3" and under and I have never heard them being called "cute", they're always called sexy and beautiful.
5'5" isn't so bad compared to those of us who are short enough to be classified as petite. At least you can walk into a store and buy a pair of jeans without having to go to the tailor's and pay a fortune to walk away with less fabric than everyone else. At least you can buy shoes without getting told to shop in the kid's section because your feet are too tiny. At least you can buy tops and jackets without the armholes being in the wrong place. At least you can buy a bike easily without having the staff complain about your crotch being too low and trying to convince you to buy the bright pink girl's bike with the tassels on the handlebars. At least you don't get all the tall women telling you to shop in the children's section even though, contrary to popular belief, short women also possess breasts and hips. *Gasp! Shock! Horror!* At least you have more of a selection clothes-wise instead of having one petite corner in select shops full of clothes that look like they were made for 90-year-olds who are constantly attending funerals. I know plenty of petite women in the world who would kill to be your height simply because of the difficulty in finding clothes that fit. You should be grateful for what you have because being an average height is a hell of a lot easier than being petite.