Fòram na Gàidhlig

Ciamar a theireadh sibh "I am at a loss" sa Ghàidhlig?

Doubt if there's a close tr*nsl*t**n that would suit all contexts.

E.g. At a loss for words = speechless = balbh

Otherwise 'At a loss' could mean 'don't know what to do' / have no solution / am bewildered etc

What context?

I do not know what to do or what to say, I am perplexed or some such thing...

You could say it like this:

Tha (whatever the problem is) a' (dubh-)fhairtleachadh ormsa .....

(The "dubh" adds further oomph)
or

Tha e a' fairtleachadh orm dè ...(whatever the problem)

or

Tha mi air (mo) chall. (Metaphorically lost) (At a loss in sense of confusion metaphorically speaking)

Or if none of those work in the context you need, then can't go wrong with a simple: "Chan eil fhios agam dè nì mi." etc

Mòran taing!