Why can’t men have hard conversations?

I don’t know what to do. Any time I ask questions or bring up a needed conversation my boyfriend shuts it down. Or he’s overwhelmed or whatever excuse he has. I give my all and I have literally tried everything. Space. Time. Patience. Anything for him to be ready for a convo that’s needed… time and time again I run into the same problem… I’m received with either “here we go again ” or meet with silence. I am frustrated and don’t know what to do at this point… I understand he has a demanding job. I understand he comes home and decompresses. But he also chooses to do all those extra overtime. During the time he could be resting… I feel alone. I feel tired for always being the one putting in effort… Urg.