Not sure what filtering options Damus has, as I am on Android. However, paring your relay selection down to a couple web-of-trust relays may do the trick, and then start adding back in a public relay or two.

If you start seeing the spam again, take the most recently added public relay back off.

A couple web-of-trust relays to try would be wot.utxo.one and wot.nostr.party