I can't comment on your masculinity. I don't know you. But it seems like you're wounded, so let's cauterize it.
In a very strange sense, it is true that males are disposable, but this fact is built into sexual reproduction by evolution itself. In virtually all species, if one parent is responsible for carrying offspring and the other isn't, then by definition the former parent is anchored longer in the reproductive act, and is thus in need of protection during that period.
Mammals in particular have an "experimental male, stable female" genetic strategy where more pronounced variation in traits (height, academic performance, et cetera) is presented in males. With each generation these traits then get folded back into the matrilineal trunk, which is less affected by them. This specifically happens with traits on the X chromosome via Barr body inactivation.
So there's one answer that you can settle on, if you want to feel really shitty. You are disposable. Society isn't responsible for this, though. The game was rigged tens of millions of years ago when some fucking fish somewhere evolved live birth. Unless you're a salmon, you've drawn the short straw.
But there are a couple of other angles worth considering.
First of all—who is doing the disposal of all these men? Women aren't the ones declaring wars, or cheaping out on safety equipment, or blocking legislation that reduces gun violence. We didn't invent conscription and we didn't bomb the World Trade Center. I mean, fuck, Pete Hegseth is systematically firing female generals and wants to stop women from volunteering to serve in the military, even if they meet all the physical requirements for service. These bloodthirsty assholes are the ones actually killing you, and they should be your #1 enemy. All of these problems are reduced by a factor of ten just by moving to Canada, where the reproductive laws are basically the same as any blue state.
Now, as for reproductive politics... I used to be a fairly left-libertarian person on this issue and felt that the real problem was that people are immature assholes to each other. It seemed to me that custody and child disputes only happen at all because the people involved had shitty parents, and that the only solution was to get rid of societal expectations; live and let live, make it easier for single moms to get good jobs so they don't need alimony in the first place. (Another "-mony" word, but this time from -monia, "condition," + alo, "nourishment.") But these days it's pretty damn clear to just about everyone that the last thing civilization needs is yet more isolation and atomisation.
I think the actual solution is to turn parenting into a social obligation. It's a little different from how things are now, but I think the benefits would be worth it.
Consider the consequences of what would happen if made the following into a moral principle: your parents' generation raised you, so you have a duty to raise the next generation. In this system, every adult is expected to have and raise 2 kids, or contribute the equivalent amount of work to paideia by helping to raise the kids of strangers, teaching, tutoring, babysitting, et cetera. This would have the additional benefits of making childcare cheaper, reducing the work parents actually have to do alone, and reducing the power and scope of serial child abusers (can't hurt a lot of kids if positions of power over them aren't a viable career.) Experts would still exist for key jobs like high school teachers.
Parents still get to choose who they hire to help raise their kids, so you don't have to worry about some weirdo brainwashing them. Since virtually every adult is going through the labor pool, there's a ton of choice. Both parents and helpers would be anonymized during this selection process to reduce biases around gender, appearance, etc.
The enforcement is as follows: anyone refusing to do this work would be slapped with heavy taxes and might even have trouble getting good jobs later on in life, the same way having no high school diploma, or bad credit, or a criminal record can haunt you currently. (There would be waivers and exemptions, deferrals if you can show you're making progress, etc.)
For parents going through divorce proceedings, most of the gendered BS goes away. In situations of joint custody, there's less concern about which parent gets priority because it isn't just 2 people raising the kids. If a parent doesn't want custody during a divorce at all, then they're basically downgrading to the "default" option of paying their debt to society, and there's no real shame in it. The one who gets full custody won't have as much of a burden than a single parent would today because the broader safety net of socially subsidized childcare exists.
