[I am being threatened]

Recently, three clients I had, who were very unhelpful, ended up cancelling their orders. In the end, before one of them cancelled, they started accusing me of being a thief for using an image that I had made myself as an example for a gig.

Then, one other client, from the same group, started telling me how "We're a global team" and how they'll sue me and take all my money. I don't know the validity of these threats, but I am scared nonetheless. I have contacted Fiverr, but thought posting here would help a bit more.

Anything would help. Advice, etc