Some reasons why you may feel that journaling isn't working for you are: you are expecting the wrong things from the practice, you are not asking yourself the right questions, you are forcing yourself to write more than you actually need to, you are not personalizing it.
There are of course more reasons why journaling may not be working well for you, be those are some very common reasons.
If you expect things that are not realistic, such as journaling being a cure for what ever you are dealing with, then you may end up very disappointed when the practice does not provide those results. Understand that journaling is not a magic trick, it will not suddenly change your life. It is a practice that takes time to get better at, to build up the patience and acceptance of the practice. It takes time to build up the benefits it can provide. Give it the time it needs.
Asking the right questions:
Are you asking yourself the right questions? Searching online, you can find hundreds of journal prompts to give you examples and inspiration for questions to ask yourself while journaling. Don't stick to the same ones if they aren't working. Try out different prompts, explore them and see which work best for you. There are no rules when it comes to which questions to ask yourself, just as long as you feel they are benefiting you and not making things worse. Try asking questions based on the reason you are journaling in the first place, ask yourself how you are feeling, why you are feeling that way, and continue from there.
Forcing yourself to journal:
If you don't want to journal, don't. If you don't have anything to write, don't. If you only have enough for half a page, or a few sentences, then write just half a page or a few sentences. The point is to not force yourself to write when you don't have anything to write. The point of journaling is not to write as much as you can, but, to write what you need.
Journaling is a very personal practice. You decide how to do it and what's best for you. Find your own way to do it. Find a spot that makes you more comfortable, that makes your thoughts flow better. Use a notebook and a pen that you like that you will want to write in. Ask the questions that get your mind flowing. Write in your own style, without fear of judgment from others. Your journaling practice is your own, and no one else's. Make it your own, however you like to do it.