Hey chrysanthemum! Hope it's okay that I'm popping in. Thanks for sharing that you do feel a little worry or anxiety about not being able to reach orgasm. It's not unusual for people to feel like any task is harder to achieve when we give weight to it or make it something we NEED to do. This can apply in any case, and can feel especially distressing during sex, whether on our own or with a partner. When we're oriented to a goal, like orgasm, instead of a feeling, like pleasure and curiosity, that can pull us right out of our bodies and into our thoughts and all the "shoulds" or "what if's" that come along with them, and poof, our embodied experience is disconnected, and pleasure is harder to reach. Orgasm becomes a task to check off, instead of an amazing treat of an experience.
I wonder if you can experiment with masturbation with, actually, the intention to not orgasm, just to see what feels good. Playing around with different positions, fantasies, tools etc. with the expectation that you probably won't orgasm might help take the pressure off, and you might find out something new about yourself and find yourself being able to reach orgasm more easily when you aren't in the mindset that you've failed if you haven't reached orgasm.
Or, you might try taking a break from masturbation altogether! Stepping away from something that is causing us stress can lead to feeling more excited to try it again, and it can help us recalibrate our bodies to what feels good when we know that it's okay to take a break. There isn't anything wrong with you, at all, for feeling this anxiety, or for being unsure why you aren't reaching orgasm. Again, it's super common. And I'm hearing that you really just want to feel as much pleasure as possible, which is great! What do you think of those suggestions?