What are the different terms for someone who has problems cutting ones losses?

Glutton for punishment. Self-destructive. Doormat.

Don’t quit while you’re behind. Persistant. Terrier. Pit Bull. Dog with a bone.

Faecal Encephalopathy – shit for brains.

Fool.

Throwing good money after bad. Sunk cost fallacy. Escalation of commitment. Knee deep in the big muddy (Vietnam War).

What are the different terms for someone who has problems cutting ones losses?

The first that came to mind was not being able to let go.

misguided beliefs

sucker, loser, idiot, disillusionment, short bus rider, a mark,
I personally like @bkcunningham‘s shit for brains
In spanish, un bobo

Obsessive, unhealthily attached, denial, codependeny, martyrdom, masochism. lol

Grudgeholders. Tenacious. If at first you don’t succeed, try try again.

It’s a double edged sword.