The One Direction heartthrob, from Doncaster, - whose 18-year-old sister Félicité died in March after suffering a suspected cardiac arrest - posted a long message on Twitter on Monday.
His sisters tragic death came just over two years after his mother, Johannah Poulston, died after a battle with leukaemia in December 2016.
His most recent single, Two of Us, is about the death of his mother.
It was released a week before his younger sister died.
In the Twitter message, the singer said: "Wanted to get this off my chest.
"Someone recently said something very interesting about how so many people focus on the 'end game' without enjoying the doing.
"I've been thinking a lot more about what success means to me.
"I feel like I've been mistranslating it for the last 3 years."
Tomlinson added: "Everything I've ever known, in my career, is straight down the middle pop.
"My expectations and aspirations are all shaped around my experiences, as much as I try and stay realistic I couldn't help but crave a 'hit' single.
"It's because of this that I've spent so long on this album, trying to fit into top 40 radio when in fact maybe I should start with what I love and work from there instead of trying to write to a more specific formulae.
"Over the last few weeks I've put a lot of things in to perspective and in fact what I should be doing is forgetting about perception and to a certain degree worry less about being defined on commercial success."
He continued: "I'm not here to compete with the likes of Drake and Ariana Grande.
"I'm here to make music I love and make my fans proud to say they're a fan.
"Turning a page today. Enjoy today and enjoy the ride!
"Don't get lost on the way up."
Tomlinson, born in Doncaster in 1991, began his career as an actor with small roles in Kay Mellor's Fat Friends and the BBC's Waterloo Road.
Appearing in a musical production of Grease as a teenager prompted him to audition for the X Factor in 2010 when he was teamed up with his band mates to create One Direction.
The band went on a planned hiatus in 2016 after the release of their fifth album to pursue individual projects.