thinking about texting my ex 28m,28f

Hello everyone, I met this girl through facebook friend suggestions and sent her a message and we ended up dating for about 2 months, i liked her alot, she was super pretty, we had a lot in common, always found stuff to talk about and the overall energy was amazing.
we met once a week and hanged out at restaurants, stand up show, pub etc and also at her place, had sex almost every time sometimes more than once and the affection and intimacy felt good.
I also got signs from her that shes interested through this whole time we dated, for example she suggested well meet more often (though it never really happened), she said that shes thankful for having me, that she miss me, if i didnt text her for a day she would initiate a text, she even initiated a meeting once, said i make her feel better etc...

eventually i noticed her taking more and more time to reply to messages leading to sometimes responding after days or even not responding at all at times (though it seems like she still tried to initiate every once a while) and i also noticed we met less often and she needed more "alone time".
i also had an overall feeling like i put more effort than her and that she dont care to lose me.
she mentioned shes going through stuff and we met once and i told her that she can feel free to share if she want to and she very vaguely said her parents dont get along well, and she decided to cut ties with her father and she even cried when she talked about it, so i hugged her and was as supportive as i can, told her how my family is shit sometimes too and that im here for her etc...
I appreciated her sharing and tried to be as supportive and understanding as i can, and didnt make a big deal about her needing some space even though she didnt explicitly mentioned it, but i felt like she didnt really let me "be there" for her either.

but eventually after some time, I did asked her whats the deal and told her that it doesnt feel very nice that she "disappears".
she said that shes sorry and that she thinks shes depressed and that she dont want me to think that its something to do with me. i let her know that im not mad at her or nothing, just asked her to respect me the same way i respect her, and if she want space its perfectly fine.

i felt disrespected because i couldve sent a couple texts trying to make her feel better (not at the same time of course) instagram reel, wishing her a good week, asking how was her day or whats up, and she would ignore these text for a few days then text me "hey, whats up" like nothing...
so she said shes sorry, and nothing changed so eventually i just stopped texting her, and she didnt text me either for about a month and a half and prior to that we also had like a month of not meeting...
couple days ago she had a birthday and I casually sent her a text saying "happy birthday hope everything is ok with you and that you feel good" with a smiley emoji and she replied positively with something like "thanks a lot sweetie" and a heart emoji... i also noticed she watched my story on facebook couple days after...
the thing is, i miss her, badly, cant get her out of my head, still wish she would text me... I think things went perfect until one day without any notice or relationship related reason it just went to shit.
I thought about texting her asking whats up and try to rekindle things... on one hand, I have nothing to loose, worst case im at the same place, and i feel like i want to text her and at least try to reconnect.
on the second hand, i think like if she really wanted it, she couldve text me herself a million times by now, especially after i just wished her happy bday it was a perfect opportunity for her to ask hows going on but she didnt...
maybe she just tried to hint that shes not that interested instead of actually saying it? i think even a depressed person would make minimum effort for someone they care for...
also, why would i "chase" a girl who don't care to lose me? who says that she wont disappear again?
what message does it send? "you can act however you want and ill be here no matter what"