First, make sure you're not being used. Girls are cunning creatures and, calling things by their proper names, mean. They are not to blame for this - they would be different, they would not have survived with us, assholes. So "low self-esteem" can be the role your girlfriend plays to make you her slave.
Then take some time to watch. The female body is subject to frequent changes in the hormonal background, and if today she is all with a low self-esteem, then tomorrow in a tavern she shakes her tits like a queen. At least two months. And ideally - to find an opportunity to glue the wallpaper together. Then everything will become clear in three days.
In general, low self-esteem and a woman are almost unacceptable things. So you need to find a clear reason for the behavior that a man perceives as low self-esteem. If it's just scary and greasy, then there are two ways: cooking and sex. And the first is a necessary condition. If she's fat, scary and doesn't cook well, then she went to some drunk or a WOT champion. This is a defective product. It's like adopting a child conceived by drunks and suffering with him for the rest of his life. If he cooks well and complex, which is still scary and greasy, then harassment with a couple of successful attempts a day. At your age, this is still real. After sex, do not hesitate to give gifts and give money. Any moral fagotism about "hold on to a prostitute" in the ass. This aunt takes pleasure in. They are much more painful when they are simply used. Especially if you yourself are not Alain Delon, but on the contrary a mustachioed drish from Fizruk. Then, if you do not reinforce the female instincts with feeding, then it will even more depress that it is not used much, and besides, no one else gives it to her.
Whoa, whoa, why be so categorical? No, of course the psychologist will figure it out on her own, what was said above is good and correct, but nevertheless, you can help such a person a little on your own, especially if you are in a close and trusting relationship.
Compliment and cheer often. An insecure person will certainly deny everything, but a) he will be pleased in his soul, b) sooner or later he will believe you. Important! Say what you believe in yourself.
Remind the girl sometimes that the so-called. By and large, "society" and other strangers do not care about anyone but themselves, and trying to please them is a waste of precious time.
Find something that would be interesting to the girl and help her (at least with moral support) to succeed in this.
Do not reproach or pressure. It is possible that she already had enough of this in her life.
And yes, you just can't help writing about it - a good psychologist can really work, especially if the matter is serious. Try to find one if you really want to help.
LEARN? Pay attention, you yourself speak of your girlfriend as if she is a subordinate creature, weak in character and does not have her own opinion. You can wean a cat from shitting in a corner or a three-year-old child to play with matches. An adult is responsible for his own life. You can tell her that you are worried about her condition and advise a psychologist. Further - it is already her business. If she wants, she will turn, if she doesn’t want to, then this is her choice.
You see what's the matter ... hypothetically, this problem can be solved. But in practice, it is very, very difficult even for a specialist to do it. Because "self-esteem at zero" was not taken out of nowhere, and with probability> 90% not from public opinion, but somewhere around 5 years in childhood under the influence of parents. And in order to solve this problem, it is necessary to somehow overcome both parental programming and the habit of low self-esteem throughout all those years so far she was a habit. And plus 99% low self-esteem is tied to some other traits of the psyche. If you take on this, you will have to spend a hell of a lot of effort, several years of time, and with all this, no guarantees of success, even if the girl will work with it herself. unrealistic for a layman.
I would not do such things. We are all people with our own problems, being a personal psychotherapist for someone is a thankless task. Let him see a specialist.
Demonstrate with examples the fallibility of crowd opinions.
Just give her the opportunity to feel most needed, etc. in love and intimate relationships.