Getting too big of HVAC equipment

I made a mistake when I bought my HVAC equipment.

I did no research and did not consult with any HVAC companies except for the one I hired.

The HVAC contractor came in, measured my home and then quoted me a price. I blindly paid and got my heating and cooling system put in. Now that I have had the HVAC for over a year, I realize that I messed up. I have an HVAC unit that is too big. What some HVAC companies do is rule of thumb. They take a loose measurement of your home and then pad up the numbers for human error. My HVAC dealer really padded them up and gave me a much too large unit. It was more of a commission rate for him, so that is why he pushed me into it. Having too big of a unit is not good, it wastes so much energy. The HVAC achieves the temperature on the thermostat super quick. It fully powers on and off multiple times a day. It runs full blast and then totally shuts down. It takes a lot of power to do this and as a result, my energy bills are skyhigh. I can hardly pay for heating and cooling because of it. If the HVAC was the right size, it would be a steady stream of heating and air at half the cost. But, now I am stuck with what I bought. It is expensive buying new HVAC. I also don’t know how to make the large HVAC run effective for my small house.

a/c representative