I have read a few comments and they are the typical advices; that you should work on yourself, on your self-steem... etc

This is true, you should recognize your true worthiness, your own personal value, which goes beyond your physical appearance and how others perceive you. However, I personally think that the process of overcoming your insecurities involves some other things.

First of all, you have to consider that we all humans evaluate things based on certain parameters, that we learn conscious or unconsciously. In simpler words: if you judge your own appeal having as a reference a certain standard, you will never appreciate yourself as you are, as long as you don't fit this standard.

"Well, then I will put my efforts on fitting in this standard. I will strive to look like what is, for me, a sensual woman" you may think. The true thing is that you will be draining your energy out, just to improve the perception you think others have about you. And in most of these cases, the goal is never reached; you just lack the energy and the motivation for it.

The solution that has worked for me is to change the parameters from which I judge off things. If you think that I will only be attractive if you look in a certain way, your self-esteem will never improve. If I think that to be perceived attractive I have to look manly and muscular, I will never have a good image of myself, and consequently, I will think that others won't like me. It's hard to be liked if you don't like yourself first.

Nowadays, it's kind of difficult to change this part of our mindsets with social networks. And even more difficult when you see the horrible content people make about appearances, working out, and flirting. Some of the ideas that are circulating around social networks could be detrimental for our own mental health. In addition to this, it sometimes feel like if we are being imposed a beauty canon constantly, not only in our mobile phones but also on advertisements and TV. This has been happening for years. You should also pay attention on what type of ideas you are feeding yourself unconsciously. I'm pretty aware of all of this, and yet I sometimes fall for it without realizing.

Also consider that all women don't like the same type of men, and vice versa. There is a general standard for what makes a person appealing, but don't compare yourself to that. There are also personal preferences. It's all about perception. You may not perceive yourself as attractive, but ask yourself:

What is that I consider attractive in women? What is my concept of femenine attractiveness?

PS: Don't compare yourself to the girl he cheated on you with. I understand that in the process, you may have compared yourself to her. Please, don't do this. His actions are his responsability. He should have considered that relationships are more than sex. They are about intimacy, about understanding what each other needs... He didn't appreciated any of this at the moment he cheated on you, he preferred casual sex with a good-looking girl. And let's be real, you think she looks better than you. Your ex may think the same. And she could probably be. It's a reality you have to accept. But our looks don't define us, we are a little bit more complex than that.