Yup, sounds like you were coming in a little hot. This can be exacerbated by using the sideslip because as you come out of the sideslip, you will tend to gain a little airspeed.
As stated above, you should land on the mains first, not all three at once.
You have to fly the aircraft and hold it off as long as possible in the flare, thus ending up with a nose up attitude and hopefully a stall perfectly as the main wheels touch down. When the main wheels touch, remember to hold the elevator where it is, DON'T push the nose down and DON'T pull back again. Keeping it where it is will naturally hold the nosewheel up and slow the aircraft down to a point where the nosewheel will touchdown on its own.
This way, you will touch down with the lowest possible speed and gain control by using aerodynamic forces. So, try holding it off even more to achieve that nose up attitude and bleed off some more airspeed. The fine touch comes with balancing holding off and maintaining altitude and not gaining altitude.