[omegajim]

I believe this is a cable clutch (vs hydraulic)

let's go from there. You described this got progressively worse in a very short distance.

My first thought would be a stretched clutch cable.

That said, before I even replace the clutch cable, the old bikes (aka, I don't know the suzuki system) there should be an adjuster (the cable will have threads on it where it goes into the clutch housing on the side of the engine) and you can adjust there.

Your bike is new enough that the cable should be the problem, or an adjustment to the cable will be the problem.

It is unlikely that it is anything more serious than a bad clutch cable.

but, that said, before you replace it, make sure you have tried to adjust the clutch cable tension before proceeding further.