How to mirror/flip an attack animation?

Hi. I currently have an animation which is basically a right-hand attack for my character that I built for my game. It currently looks like this:

I’m very new to animations & Blender and was wondering if there is any way to mirror/flip this animation so it’s a left-hand attack? I’m basically thinking of a dual-wield system and I must figure this out first so that my character does the right-hand attack first then the left-hand attack that I want to create.

Is this possible? If so how can I achieve this? Playing them in reverse in UE4 is an option but looks weird. Thanks in advance.