I wouldn't have thought that arthrotec would make you feel drugged out, though with your other health problems it may have different effects than it does on me. It may be a painkiller, but mostly its an antiinflammatory. I've had several different antiinflammatories (NSAIDs) at full strength and they have never made me feel at all "drugged". The codeine or other stronger painkillers can give me a drugged feeling but not the NSAIDs.
Can you try the arthrotec at the full dose on your next days off, just so you can check what it feels like for you and make sure you do feel that you could still be alert enough to work.
I'd echo the comfy shoes and insoles though - you want as much "springiness" and cushioning under the soles of your feet as possible.
