Hey there. How is it going for you thus far? The Gabapentin withdrawal should be taken somewhat seriously, but if you are doing fine with that much of a drop in just days you should be just fine. I was taking - at the very least - about 2400-3600mg a day for roughly a year and a half. I knew when I needed it, that's for sure, but the w/d didn't effect my anxiety too-too much. The odd sensation of a bit of a hot flash would hit me and I wouldn't feel comfortable in my skin, so that meant I needed to dose up. Typically 600-1200mg at a time. I could never tell how bad it would possibly get because I always did have Gaba to take (the VA gives ridiculous amounts to me at a time) but I never really wanted to stick around that grey area too long and find out. This last year I was completely detoxed (for alcohol, anti-depressants, anti-psychs and the large amount of daily Gaba) and went into a treatment center. Once I was in there they prescribed me Gaba again for nerve pain and of course the anxiety that I took it for prior and I was taking 600mg x2/day and 1200mg @ night. That's fine and dandy or whatever but I had a lot left so I would have a "fun night" and get up to maybe 1800mg and could feel the effects for a pretty good amount of time, but your tolerance creeps back insanely quick so I started decreasing again and could feel that mysterious w/d sensation to go grab my dose and feel A-OK.
Having all that in mind, I believe that you will definitely be able to differentiate the two separate w/d, BUT I would not drop the dosage so rapidly. Do maybe 300mg drops every week for comfort. If you haven't been taking it for longer than 9-12 months I wouldn't worry too much. Perhaps some heightened anxiety or depression with a little bit of disrupted sleep and body discomfort. Nothing you can't handle after getting off the heavier drugs you had been on for such lengths of time.
Hope you are doing well with your taper!