It doesn't matter if you spend more time than your opponent in a game. What matters is that you're spending the time effectively. The more complex the position the longer it's going to take to find the right move.
Where are your spending time time? And why? What is it you are thinking about? Are you double-checking, or triple checking your analysis? Or are you analysing as many moves as possible? Also look at the types of position you spend more time on: is it opening moves, is it positions right out of the opening, is it tactical positions, quiet strategic positions, unbalances positions, dynamic positions, or maybe positions you feel like you have a substantial advantage and you're trying to find a win?
The key is to bring discipline into your thinking, and train yourself to make a move quicker. First step is to figure out which position/moves the time is being spent. Then to figure out why. That why could lead you to identifying lack of knowledge/experience of a particular type of position -- maybe a weakness in your play. That means you can train yourself to get better at such positions, gain some confidence, and make it easier to find the right move quicker.
However, if you are spending the time double- and triple-checking your calculations, then it's a confidence issue. Something like Kotov's book "How to Think Like a Grandmaster" might help, to start training yourself to analysing a variation once, and only once, and to trust your calculation abilities. Perhaps calculation training is all you need.
If the reason for the time being spent is in the middle game trying to find a plan, then finding annotated games by grandmasters in the same or similar openings might be the solution, to give you more familiarity of the positions. That will help build an instinct as to the right kinds of moves and plans to play.
If you're spending a lot of time in the opening, then maybe spending time studying various opening systems you are playing to get a better understanding of them, e.g. playing through annotated master games.
And a steady diet of calculation, both tactics puzzles and endgame calculations. Chess is very much a pattern-recognition problem at the human level. And discovering patterns in study will help spot them in play. Building that instinct to the correct move, and then using calculation to verify your instinct is correct -- that's the Magnus Carlsen school of chess.
