Greetings,
If your airplane controls feel too jerky, they are working as intended. You are supposed to use small, smooth corrections to make the airplane do what you want it to do. Using small, smooth corrections also limits pilot induced oscillations. Think of a car on the freeway that isn't going straight within its lane, perpetually ping-ponging between the lane markers. Overcorrection is especially easy to do in a simulator where you do not have the tangible feedback of G-forces, the winds acting on the airframe, or the buffeting of the wings in high-G maneuvers. Trim is also to be used lightly. Put the aircraft in the attitude you want, and gently add in trim until you do not have to make any corrective actions. It may help to hold backpressure on the stick and, as you trim it out, release the backpressure until the airplane is holding the desired attitude effortlessly.
It is also advisable to be aware of your power settings while you are doing this. If you are maintaining a constant power setting, you only have to trim once. If you move the throttle, without touching the stick, the airplane's pitch will increase or decrease correlative to throttle input, and you will have to trim it out again to compensate. A useful mnemonic for grasping this concept of cross control is "pitch for speed, power for altitude."