Struggling with ADHD friends

So this year, I've made 3 new female friends who all have adhd (one of them is someone I used to go to high school with so not someone "new" in my life per se).

I've found myself in the last 2 months or so really struggling with all of these friendships individually and I don't know what to do. I really really really don't want to have a conversation with them around it, despite knowing how this is not conducive to healthy friendships, because deep conversations overwhelm me and because it's things they can't change, I worry about upsetting them.

I'm just really struggling with the inconsistencies and things not adding up. The constant, "let's hang out soon, let's meet, let's do x,y,z" only for it to not lead anywhere. I'm so dysregulated (I think that's how you spell it) over the energy changes communication wise (like we'll meet and have long, deep talks and I won't hear from them for a while, or we'll message frequently for like a day or two, only for the communication to drop off and I won't hear from them for days or weeks (and there's no pattern I've figured out so far as to what leads to this). And it's so hard for me to wrap my head emotionally around someone saying they want to hang out and do stuff only to respond hours later that they were busy with something else, or to have plans be cancelled. And what confuses me more is when we talk, we seem to share the same desire for close friendships but I feel like this doesn't align with their actions because whilst I logically understand they have adhd, when I hear that they talk to their other friends daily or every other day, but forget to respond to me for days or weeks due to adhd, it's hard not to take that personally.

As someone who goes off of people's actions to tell me how they feel about me, it's hard to adjust to these friendships because to me, they look the exact same way fake friends who don't like you but won't say so.

Does anyone have advice based on their own experiences? So far, I've been leaning into not having them be the core part of my life as I need consistency here (so I focus on myself, my plants and the local birds), and I've also been setting my own time boundaries (I.e. if they message me to hang out and I confirm I'm free (or vice versa) and they don't respond by a certain time, I don't meet them as I need some notice in order to not feel stressed), and clearly communicating how much time I can spend hanging out (usually a max of 3hrs) so that I can have time to self regulate and reflect.