The problems isn't that.
The problem is that girls instantly lose respect for you when you show them your emotions. So you cannot really be let' say "emotionally honest" to them.
I could wish it was like that (because it would just be easier too etc.), and then that you really loved you for the person you are (e.g. non conditional love), but that is not how it works. Women love conditional, that's it. That is what they feel for you, right now and what you do for them right now.
We men are destined to walk the lonely road of life; sadly but true. You are way better of crying in-front of you parents, sibling or a very close buddy. We all cry sometimes, but as guy you just cannot do it anywhere and everywhere like girls do.
The basic problem is that women has no understanding or sympathy for men's emotion or what it is to be a man. Call it toxic femininity if you will... Women do not give a shiete about your male feelings. They might lie to you and say that you want men to do it, but watch their actions and you will see they lie to you because they really do not want that.
Being emotional is as we all know a female feminine trait. If a guy behaves in a feminine way then both women and society condemns it as we're expected to be "The masculine rock" at all times.
I am still not 100% convinced on this one. I can see why it's better not to get swept in the emotions and I agree.
A few months ago I became frequently sad if I saw people being happily together as a pair or in groups. I would then shove the emotion deep down and put up a face of stone, until I was in "safety".
Some years ago, I was doing a travel vacation. I left a city where I had a very good time and felt included in a group of people. I arrived at the next city, feeling very sad. On that vacation my self esteem had sky rocketed from constant self validation, so in this city I was comfortable in displaying my sadness openly. I remember walking to the port getting emotional, and then crying at the water because I made it to the sea (I started my travel at another sea). Then I did a tourist thing and met a group of people. In the evening, they did a tour. I was reminded of my loss in the city before, and became sad again. There was a picture with the whole group, and my face in it was like I was about to cry. Later that night, the girls in the group repeatedely asked me, if I was "having fun". I didn't open up, I thought they were covertly telling me they are uncomfortable with me being sad and wanted me to go. In hindsight, I think they offered me a helping hand, too.
Despite this being a night I kind of feel ashamed of now, I know it was one of my strongest. I was never again that sure in myself to display my vulnerability that openly. But that night, I did.