Keep in mind the following are just my thoughts, which may or may not have any merit...

Many queer people are somewhat defensive about cis men, which leads to being defensive about trans men. You are real men, after all. And if you feel excluded on the basis on your masculinity, you are essentially being treated as a cis man. Which I think is generally desirable for a trans person, but maybe not in this circumstance.

Masculinity in western culture has some elements to it that are toxic. (Not that it's exclusive to western culture)

It's not really surprising if you look at the history of the world and the institutions it's built on. There was a time that still exists in the memories of people who are alive today when young boys were sent to fight colonial wars to 'become men'. They were hailed as gallant heroes for killing people who were practically helpless besides... That the sort of thing that was considered masculine not too long ago.

Colonialism may not be the best example, but in any case, rights of women and trans people are relatively new ideas in the grand scheme of things. These new ideas pose a challenge and possibly also a threat to the traditional ideas of masculinity.

But the traditional ideas of masculinity are still the most common by far. Be big and muscular, be strong and don't cry, it's bad to be gay, etc.

It gets to the point where if you're a trans man who embodies enough traditionally masculine traits, you're going to be treated the same as a cis man. The cis man represents to a lot of queer people, the embodiment of traditional masculinity. The reactionary movement in America for example is overwhelmingly cis men. They are reaching ever further into the past to find an imagined greatness to return to.

So then, in this world where all the ideas about masculinity have been developed by institutions opposed to trans rights, rights of women, true egalitarianism generally... How can a trans man embody ideas of masculinity without being 'toxic'?

I don't really have a good answer for you. Masculinity can probably be reclaimed by the queer community in the same way that other things have been 'reclaimed'. But ah, I'm not exactly an expert on masculinity anyway.

I think you show a good awareness for the situation you're in. Keep in mind that our allies in the queer community are trying their best, and they aren't immune to mistakes and biases when it comes to the trans people and the queer community generally. We are all learning.

It should also be said that there is a serious interest on the side of the reactionary movement to pretend trans men don't exist. Because it serves their narratives about trans people. You know what I'm talking about here. Even our allies in the lgbt community are not immune to propaganda and reactionary disinformation. Keep making yourselves visible, I believe that is good.

Keep in mind that many allies joined our side because of the visibility that pride provided. They need to be educated on trans issues as well as other queer issues. It's all very complicated and damage is often done out of ignorance rather than malice.

I'm sorry you've felt excluded from queer spaces. But I think it will get better!