Pilot reported engine roughness and unable to control engine RPM after take off. The Pilot requested priority handing and performed an air turn back and precautionary landing at departure airport.

Narrative

During preflight and taxi; everything was working normally. Nothing was out of the ordinary. I taxied from the FBO to Runway XX via Alpha. I proceeded to execute my engine run up. Again; nothing seemed to be wrong. After about 4 takeoffs and 2 landings ahead of me; I began to start the takeoff. I pushed full throttle but the plane seemed to be slow in accelerating. There was engine roughness and aggressive shaking. It has happened before where there has been some slowness in acceleration and engine roughness but as soon as you get off the ground; everything is good. I also thought it could be the nose wheel shaking; causing the shaking of the plane. I reached 50 KIAS and rotated. As I rotated; the stall horn squeaked. I lowered the nose and attempted to gain airspeed to climb. However; the rate of climb was extremely slow. I noticed the RPMs have not increased past 2;100 RPM. With this as well as severe engine roughness; I decided I needed to return to the airport.I made the radio call as follows: 'Tower; Aircraft X is facing extreme engine roughness and is struggling to climb. We would like to return to Runway XX'. The controller advised me to turn downwind when able. The height to turn downwind is 700 feet and the elevation of the land under the downwind leg is around 500 feet. I was unable to climb higher than 400 feet in the two minutes I had been in the air. I then said; Aircraft X; we are not able to climb high enough um is it possible for me to turn around and land on Runway XY?; which is the opposing runway of XX. The controller approved this and cleared me to land on Runway XY. I turned around while configuring for landing. He asked if I needed any assistance to which I said that I did not. I never requested priority handling because the engine was still running just not at full power. I landed safely and taxied back to the FBO via Alpha. I shut down the engine and downed the aircraft to get maintenance to look at it.