I would suggest to ignore the entire concept of "masculinity" and just focus directly on what you were trying to achieve by using that concept. I see several things in your text.
1) You had an abusive father who was unhapppy that you did not fulfill some ideal that he had in mind. That left you wondering about whether you could/should have fulfilled that ideal better, and how it actually works.
Here my recommendation is to abandon this entire line of research. You can't change the past. Even if you figure it out, you won't get a second chance to do your childhood right and have a better relationship with your father. (Plus there is a chance that in a parallel reality where you were properly "masculine", you were punished just as much, only for something else. Sometimes the things that happen to you are not about you, but about the person doing them.)
Get a therapy. Realize that you desire something that other people had but you didn't (an accepting father), realize that it is a valid desire but you are not going to ever get it anyway because sometimes life sucks, cry over it, then move on, and focus on the things you still can have.
2) Some behaviors are virtuous; helpful to have a better life as an individual, or to be a better member of a society. Identify those behaviors; judge each of them on its own merits. Do not worry about whether they do or do not fit into some abstract concept of "masculinity".
You were already getting to this conclusion yourself, I am just expressing my approval, and giving you a blessing from an external masculine authority, if such thing might help you emotionally.
Physical strength is useful per se. (I also know a few women who do strength training.) Mental strength is useful per se. (And just like you can fuck up your body by doing the strength training wrong, you can fuck up your mind by doing the mental training wrong. For example "perseverance" and "stubbornness" are the same mental strenght, the difference is whether they are applied towards a worthy goal.) Therefore do become stronger, but do not worry whether it fits someone's concept of "masculinity" or not.
3) Yes, sometimes old concepts are obsolete, because they were designed for a different situation.
4) Yes, developing skills takes a lot of time, and you need to reward yourself all along the way, that is how conditioning works in humans and animals alike. And then give yourself an extra reward for actually achieving an externally measurable milestone.
Then there is also one thing that you do not mention, but in my opinion it also belongs under the topic of "masculinity", which is sexual signaling. Things like wearing stereotypically male clothing. It does not have to be better per se, it's just a way to signal social conformity, which is sometimes useful. (Smart people choose their battles.)
This is an interesting exploration, but probably not framed right for LessWrong, and it's missing a LOT of awareness of variance across individuals and cultures. Because it's written as if it were one thing with an actual truth behind it, rather than a set of roles and expectations that shift based on context and are different for each pair (you and your dad being a different set of expectations than you and your classmate or you and your lover), it's very hard to agree with or object to any particular statement.
It's incredibly incorrect for some of my experiences, and somewhat recognizable for others.
This isn't a bait of some sort, but rather just a self-realization on how we view masculinity. I, for context, am a man, rather a boy who was not treated fairly in regards of being a man.
Growing up, I wasn't treated well by my father and I would often get the belt whenever I showed signs of femininity or any emotions that could lead me into crying. I had thoughts whether or not I was wrong for having those things, or if being sensitive was wrong. The truth is farther from that.
The idea of masculinity isn’t necessarily about being the biggest and the greatest to the point wherein natural selection won’t affect you due to how godly you are in any sense. Moreover, it is about the responsibilities, not how you present yourself. Yes, you could exhibit feminine traits, but that does not make you less of a man.
There is no reason for you to be dictated by traditionalist ideas archaic in the contemporary world. One must go against the flow of the seas, for getting dragged along with rough waves makes you less of a person with an identity. Going with the flow is a sentiment I undeniably loathe due to how pretentious it sounds. Your life is malleable by you. Just because many people are going through with one thing, that doesn’t mean you must follow suit as well. It makes you no different from the people of the previous years and those in the current world.
Similarly, masculinity is not about being the strongest physically but can also mean being strong mentally. Being strongly willed is something most people are not used to hearing. Yes, you could argue that the sentiment “ mind over matter “ overcomes this argument, but I digress. Mind over matter often refers to situations that are supposed to be succeeded in a physical form, but not over the concerns of the heart. We have been trained to go beyond the feeling of physical pain but not to go beyond and understand the problems of the heart. The heart is often disregarded by the concept of “masculinity” because the physical form is superficial and easily noticed. That, in itself, hurts the innate emotions and feelings people have.
We must not let the previous ideologies hold us back. We might not even think about it, but maybe in a few years time we will be the ones who are unreasonable to the current generation.
Masculinity is not about being all physical, it is also about knowing what you are and what you can feasibly achieve. It does not mean that you must be content with being weak per se, but being able to understand those weaknesses and being able to do something about it. I have been afraid of spiders since then, but slowly I have been regaining a stable wavelength in handling that fear. Being masculine does not mean you can immediately shift into a powerful being, but a process that takes time and effort to understand yourself. Taking care of yourself doesn’t make you less of a man, it is a basic human function that everyone must do.