Basically my best friend is now in a relationship with a guy I had an open relationship with 3 months ago which I only accepted because he was my fp so I just basically had to agree just to have him close. She and him are also in the same group of friends and I see them daily. Apparently he took some lsd and he got enlightened so he decided to get in a relationship. They never even told me anything, they just started being all lovey dovey and told me after I asked her to tell me and pushed her to actually tell me what is wrong! (In my defence she said "I need to talk to you" and then wouldn't tell me so I couldn't just wait forever). Going back to my country (see 5) I decided to not talk to her, I realised that this needs to be rediscussed when we are back so I decided to talk to her as little as possible and not discuss this. So back to Greece now to my shitty home (5) she kept messaging me asking me stupid favours like to get her some clothes and creams from her family and bring it to her. She made her dad call me as well so I genuinely found it very hard to say no (see 1). Her selfish requests consumed at least 30% of my time. Now think that I had to run daily with public transportation because I can't drive, to banks and lawyers and also have in my mind to pick up her shit making me travel hours everyday returning home exhausted. Not only that she kept pushing my buttons so I would talk about that issue. She just couldn't respect that I needed my fucking time. That's not just in my mind, she just kept mentioning things indirectly related to this guy that would trigger me or bring it up by saying "i know our relationship is damaged and it just makes me very sad" I still thought I'd stay the better person and ignore it until I'm back! Until she told me yesterday that she can't wait for me to come back for my bday because she has great plans. At this point I snapped because I would wipe my ass with her plans. Maybe they can think of not hurting me like that instead of organising things for my bday! I don't need gifts or surprises I just wanted to be happy for my bday and they already ruined it! I just find it a bit superficial. Is it that bad that I just want to have a nice bday with people I'm comfortable with? I'm sorry I'm so inconsiderate for your plans about MY birthday. So I sort of said that I'm uncertain about whether I wanted them there for my bday. She snapped at me "telling me that I'm being rude and inconsiderate and that they took time to organise it and that they are we're going to be considerate for that day" (btw she just changed her whatsapp photo to a photo of them like she's trying to rub salt to the wound) Now basically my friends are telling me I'm dragging this too much! That feelings "just happen" and that I said I didn't like him anymore. (See 2) My issue was not as much their relationship (I want nothing to do with him anyway after that) but mostly that they were my friends that know I have severe mental issues yet their way of dealing with this and timing was just so inconsiderate it blows my mind away. Am I being irrational? I tried to give as much of an objective perspective as I can here but I honestly am questioning whether I am a bad person or not. Am I being selfish, manipulative, irrational?? I honestly don't think so but please tell me if you think I am! In not one of her messages did she actually show any humility or signs of regret. If they just "fell in love" or some shit then it's the same for me, I just don't feel like I can be friends with them anymore. Why does the same excuse work for them but not for me? 

I'm seeing them tomorrow as I'm travelling back and I was going to tell both of them that i want nothing to do with them anymore. It sucks because I have to break the group but I just can't get over this. It breaks my heart, I have been so suicidal because I am scared of becoming the bad guy. My other friends are already back so I'm scared that she and he will fill their heads and propagate them into hating me. I'm so paranoid I'm so scared I don't know what to do :( I want to be friends with the rest of the group, but I'd probably go back to my hell and Isolate myself and i honestly believe I'd commit suicide because this is how bad I feel. My birthday will be a particular trigger as well. I've been thinking about this for days and I'm scared that now I'll be alone I'll have plenty of chances to do it. I've always thought of suicide, came close a couple of times but I've never actually been scared I may go through with it. On the one hand I don't want to die I just feel so overwhelmed I'm scared I might just cut deeper when I cut or take more drugs than I would and OD. 

Important information:
1) I have important business relationships with her family 
2) I said I didn't like this guy (but it was a total lie I was just trying to convince myself and everyone else just because imagine how awkward it would be being in the same group of friends and everyone knows I still like him)
3) I actually was doing great getting over him, it's been 3 months and I accepted that he wasn't ready for a relationship and we actually became really good friends but now I feel like all that progress has been ruined. 
4) I completely dissociated when she told me she was thinking of dating him because it was such a shock to me.
5) my family situation is terrible and everyone is aware. I had to travel to my home country one day after this whole thing happened because my family and financial situation is terrible. I went to my home country to a very stressful environment having to deal with financial issues in a home where whilst my parents are trying their best my dad is at the hospital and very sick and my mom has a lot of anxiety and it's just not a loving home because everyone is so stressed about money they take it out on each other. 
6)my birthday is in 2 days and I've never had a nice bday so I've said that to everyone and I was hoping this year we could all have fun together and just maybe drink and do some light drugs but I didn't want anything fancy I just wanted to feel loved, like part of a group that cares about me.

TL;DR: my best friend got in a relationship with someone who had an open relationship with me because he wasn't ready for one. We are all in the same group of friends and I feel so sad and betrayed. She keeps triggering me because she wants to get a reaction and now everyone is attacking me and saying that I'm dragging this for too long and I am so overwhelmed I'm scared I might actually commit suicide. Any advice much appreciated! 