Is there anything I can do about my appearance?

Newer friends and people I just meet say I look depressed, I don't walk straight, and I look like I don't have any self esteem.

When I ask my family and longer term friends, they say the opposite.

So, I have no idea which one is right but I get this a lot and it's irritating cuz it's not true and it makes it awkward talking to them afterwards because they're all trying to "help me" and I don't know what… needs to be helped…

Like I get advice to start saying something good about myself while looking in the mirror while I'm undressed and everything like that and I feel completely fine and I already subconsciously do that anyway… -___-

It's really irritating and I don't know what to do about this. What am I supposed to do?