I always hated running, but I had always been doing it for exercise. Perversely, this meant if I moved inefficiently and made the movement harder, I was doing better. I characterized running as "competitive suffering". No pain no gain, right? And like you, I always did more than felt good, and figured that meant I was doing it right.
But I don't think that way now. I want to enjoy moving. I want to move playfully and powerfully and efficiently. Exercise until it feels good, not until it feels bad. Love the body you have and take care of it and build it up, rather than hate-exercising to change it.
I went through the same paradigm shift with cycling. I used a cheap bike that was slow and heavy because higher efficiency wouldn't allow me to get exercise any faster. Then I got a nice road bike, and it's so much more fun to ride, so I'm riding a lot more.
But I don't think that way now. I want to enjoy moving. I want to move playfully and powerfully and efficiently. Exercise until it feels good, not until it feels bad. Love the body you have and take care of it and build it up, rather than hate-exercising to change it.