Welcome to Beyond Blue and thank you for coming here and providing your post.
It does sound like an awkward situation that you’re in and that friends shared can be really difficult to deal with.
The relationship is over but you need to get over it in your own way and in your own time and yep, if someone tells you that ‘you should just get over it already’; that kind of thing does not help one bit.
Is it possible for you to stop with the social media thing for a while? Ie: so that it may reduce any change of you seeing him and whoever else??
Is it possible for your best friend to stop with giving accounts of what he’s up too cause all of this are just factors that are feeding your wound; or rather pouring salt on your wound.
One more suggestion: would it be possible for you to arrange a small get together or dinner or drink session? And when I say, small, just invite a bare few friends, just so you’ll be able to go out and enjoy their company without having the fear of bumping into ‘you-know-who’.
Just some thoughts/suggestions. I do hope you’re able to post back.