Hello! I have been having some... trouble, and I was wondering if anyone here would have any advise.

-I have a friend that is really dear to me, they are the first real friend I made, the first person I came out to (trans), they more or less gave me my name, the first person to return to me and apologise for ghosting me, the first friend I meet IRL and we have been friends for 5 years.

-a few months before this year I have started having feelings for them, I basically can not stop thinking about them at all there are no words to describe how much I want them, to most accurate word for how this all feels is "yandere".

-a year BEFORE I started to feel like this for them they went to visit some guy in the UK and fell for him, and they went meet him for new years even and they got together. (note that me, them and that guy are all from different countries)

-I tried to write a letter to them about how I feel before they went to see that guy again, in the hopes that we could talk abot it directly, however all they said if I want to be closer to them or date them I should just say so and that they would not stop being friends with me over it. I tried to talk about it again since I wanted to have a conversation about it however they did not say anything, after they got together with that guy I said that I wanted to talk about it but they said that there was nothing to say and that they had nothing to say about it. After wards I said I did not have feelings for them anymore (witch was not the case, I don't even think they beleived me) and we went on to talk like nothing happened.

-for a month or so things where relatively normal, with the exception of them randomly talking about how much they miss that guy, witch felt really bad for me to hear, one time they even mentioned how taht guy called them attractive witch felt really shitty cause I also feel like that, however I feel extremely guilty about it, so the fact that that guy can just say that, and get a positive reaction while I was unable to speak felt horrid.

-However at some point they had to go offline for about 10 days to focus on school stuff, I was fine with this since I was informed of it before hand however they where gone for about a week more, then after that they barely spoke with me, trying to get more then a sentence or two out of them felt like trying to get blood from a stone, and nearly every time I asked what they where doing they said that they where on a voice call with that guy, eventually I managed to have a conversation with them where I asked if I could meet that guy, they not only said that I could not, they said that they do not want anyone they know (except their parents) to interact with that guy, they also said that they only people that they know who know that they are together are me and their parents, all of this is REALLY strange to me and to basically everyone else I tolled about this. After this conversation they have ghosted me and they have not said a word to me since. It has been more then a month.

-I got to talk to a common friend of ours, witch I get to talk to about once a blue moon, and they said that this person that I like is busy with school however the fact that they are online and playing games nearly every single day, and staying up much later then they used to (no doubt talking with that guy) makes me doubt that they do not have enough time to let me know what is up.

-(I assume stalking is like, a somewhat accepted thing here since this place is literally called "yandere community") I've tried to use some email search sites and apps however I haven't found much they barely have an online presence so I have not been able to find much on them. I tried to re-downloaded a genshin impact since they play that game (we meet on it) and I tried messaging them there but they didn't respond, and now I feel really bad about it since I must look weird or desperate because of it. I also have a friend who offered to get that game to "accidentally" meet them and talk to them but I realized that it would take too long for that to happen (they would need to level up their account enough to be able to play with them) so that plan is more or less out the window.

I am really sorry for the long text, but I just don't really know what to do, people have tolled me to just give up and let go, but I just can't, it's like they are stuck in my head, I know it would be better for me to give up but I just do not want to, I am actually scared that I would/will stop having feelings for them or start to resent them for leaving me like this, I wanted to find that guy to try and either find some dirt on him, or to find a way to break them up because the idea of them being with him makes me want to tear my skin off, that is why I tried to find their social medias, with the idea that I could maybe find him but I haven't had any luck.

I know that there's probably not much anyone can do or say to help, but I am mostly asking if anyone has any advice, either in ways to find information on someone or on how I could maybe get them to talk to me again, or any other sort of advice, I am really sorry for all this mess and for asking so much and thank you for reading this far if you have.