Not really sure if you're saying you're looking at people's erotic zones or you're afraid they're thinking that's what you're doing. I mean, we all do the former, though most of us do it from a distance. All living things are highly sexualized or there wouldn't be any living things, if you get my drift. Some like to pretend they're not out of religious or other ideological beliefs, but life basically eats, sleeps, finds shelter, and has sex. Everything else is from the human imagination, as we developed this cerebrum that allows use to create a lot of artificiality in life. Some of that is really fun and really profound and some of it is just vast amounts of time wasted, but it is our lives. It's another thing altogether to be so bothered by it that, one, if it's offensive you just learn not to do it, or if it isn't, you make yourself miserable over something you may be the only person who is noticing this. My wife and I are both in our sixties and we still look at attractive people and their attractive parts. But we don't stand and stare face to face at them. But you don't say you're doing that, you say you're afraid people think you're doing that, or you're afraid you're doing that when it might be you just tend to look down when you're close to someone. That could be insecurity or as someone mentioned shyness but it's not a major thing. So which is it -- you're obsessively staring at people's erotic body parts or you just think they think that's what you're doing?
Hello there
Think of it more as your mind trying to explore and seek information that it desires to find out which it thinks would possibly lead to somewhere that allows you to satisfy those desires. Or just simple curiosity. No need to stress yourself by overthinking unless you are just questioning yourself alone to know better about yourself, which you ultimately will even through observing your actions over time. Like they say at this young age the mind is like a sponge that just tries to absorb everything. I also suggest you giving it food such as books etc as supplement. Avoid literature that is related to intimate activity or media like that. The world right now especially internet is full of all the crap that suggests or encourages such type of thinking that lays importance on such subjects directly or indirectly. Everybody is trying to sell something by focusing on something else that may not be even true. Anyways,
it's normal, happens all the time to almost everyone. But what matters is how you react. Be strong! Sometimes what we see is what we are. And we may be unsure about ourselves that reflects in the way we look at others. Being strong allows us to enable to help others too. Help them to feel sure about themselves. Me, I am trying. It is a task that is never over but with time as you get to know yourself better , you enjoy the company of yourself as well as others.
It is the way mind works especially at an age when the hormones are at their peak. And with time as you get to know yourself more, especially If you practice self control, even your mind will start to know that such behavior would lead to nowhere. So it just stops and knows how to ignore such impulses. Or it simply doesn't matter anymore. In other word maturity to not allow any stimulus from outside to change your reaction otherwise. Have belief in yourself. Maintain a healthy lifestyle such as exercise etc to feel more confident. I mean there may be a time when people who will be like you were and they their focus could shift unintentionally on your chest area. And that is the time you will have to be confident enough, again without bothering yourself. That is the time your reaction will enable someone to get better like you did.
Take care
I have a lot of social anxiety, too. It's normal. The best therapy is "Cognitive Behavioral Therapy". Practice making eye contact and paying attention to all the information the face and eyes can convey. That is a good way.
Also, you can always joke "I am shy" and show bashful behavior. That is a cute way to make it funny, especially if you are a girl.