So you invested 3rd hand in an unregulated generally untrusted investment with many crooks around, you knew you had no redress legally and now you are paying the price!
Crypto is mostly unregulated. Sites such as Binance are full of victims.
Bitcoin etc is fantasy land! Thr more it is popularised, the more scammers take your money.
It will be impossible to make a case...who with, contracts etc, what country, is it a regulated financial instrument? No, never!
It sounds like your friensd you invested in is/was trustworthy, however it is likely he is also in over his head having also been ripped off!
You know of course the saying "Friends are friends and business is business and the two should never be mixed"
Sorry, but the saying is "If it looks to good to be true, then it's a con!"
Good luck!