Have you considered a wall wart (rated to twice the current you actually need) plugged into the light socket using an adapter powering some LED strips?
Yes I have - in fact, I got a pair of the LED strips already (240 per strip @ about 900mA), but wife didn't like the idea of having strips on the wall. I could keeping them in the bowl but the dots of bright randomly placed inside the bowl looked awkward.
So, I have a pair of strips unused. As soon as I get around to it, I plan to make a few long alligator clip cords to use the pair as emergency light with my car's jump-booster as power source.
Check the power quality - transients and sustained overvoltage might be suspected. 6 months is much too short even for the cheap stuff.
After see this post, I was more alert. An infrequent slight blinking my lights a caught my attention (twice, sub-second off then back on).
I know this happened before, frequent enough for me to remember but I never put much thought to it thinking it may be wind-caused tree branches brushing the power line. We do have frequent (once a year or so) high-wind caused outages.
I have to pay more attention to such quick-blink from now on. The in-coming power may be less reliable than I thought.