Hey there
In june & July I bought Digibyte & Stratis & Siacoin with all my bitcoins, till now I lost almost 80%
What can I do, HOLD or Sell or What!
don't wanna suggest too much. from my side in such situation, I will hold those position. I am personally still holding strat.
You should make such an important decision yourself, because you have to live with this decision, carefully weigh all possible options.