I think it's because of pauses. If you don't draw in couple of weeks, it becomes more difficult. In my case, at least.
Hello Morgan,
Beautiful line and nice drawing. Just keep drawing. You'll get your own style automatically. The upper arm and upper torso are maybe too short.
One option is to upload image to this site (in Your Studio).
Then paste the link (from show off your image) to the text.
I don't see stiffness. The gesture looks natural and the line has a nice variation. What if you forget the clock and draw the hands and the face more accurate. It makes the whole drawing different.
Drawing should be fun. Draw topics that interest you.
Be careful with the eyes. They easily become over-emphasized when you draw a full face. I mean if you want to draw a realistic face.