You probably can't counter sue for the services provided. She gave you a gift and you accepted it, that's the essential issue. It was your choice to move it & set it up.
Since she intended to give you the gift, I would think the gift is irrevocable.
You'd have an easier time if you had a note from her stating that she was giving you the pool table. However, since you've had it for 28 months I would think it's yours no matter what.




