Welcome to my world. I'm 6 feet tall and weigh 160 lbs. The hollows of my neck, the spots below my ears next to the jaw, and the jaw line from the ears to the chin are where I have trouble. Basically, I--and now you--have difficulty shaving any feature with high curvature.
I follow the advice provided in previous threads regarding difficult spots (e.g. lots of stretching, moving the skin away from the jaw line), however, this takes time. My compromise is to use a DE during the week and save straight razor shaving for the weekends when I have all the time I need. In some respect, a DE is better because the razor is more maneuverable. Consequently for me, a DE shave with a fresh razor rivals a straight shave.