Taking a pain killer along with Gabapentin or Lyrica, usually produces
a reduction in pain levels. (A Cocktail)
300mg of Gabapentin is a starter dose (3xday?=900/day). 2700/day (900x3) to 3600/day (1200x3) and more is not unusual.
I take Lyrica + Tramadol (Ultram), others use different meds.
There are over 75 different meds used individually, or in combination- to treat PN.

Mine started as a sharp burning sensation in my upper middle back. I then felt a strip of burning down my inner left leg. From there it spread all over my body in a matter of six weeks.

My worse areas are my back, stomach, knees and lower legs. I also have it to a painful but still lesser degree in my feet, arms, and hands. I am seven months into the disease and at present I have no numbness or muscle weakness.....yet.

What makes me feel better:

Distraction and keeping busy. Walking around.

Better weather. High pressure and low pressure systems affect me.

Warm baths or showers.

Using a cooling gel such as Calendula gel. Very soothing.

I also take 1800 mg. of Gabapentin and Vicodin as needed. The Vicodin helps more then the Gabapentin.

Recommended supplements listed on this site.

Avoiding sugar or too much caffeine.

I think we are all different in many ways of what helps and does not. I will say too what someone else stated that 300 is a very low dose so you may feel better if your doctor begins to increase or adds a combo of other meds. Also since you are stiif like I am too so stiff a possible muscle relaxer you may want to ask about.
For me I am not sure what is my PN pain and what is my RSD pain or the unknown.
I will say what makes for better times is good weather,proper amount of movement, sometimes as needed meds,baths
Worse invasive procedures,bad weather,tests,too much activity,touch,wrong material on legs