Hi kokoPeg, welcome to Scarleteen. I had a look at both of your posts, and have approved this one as you mentioned that you prefer the way that you have expressed yourself here, so that there is one thread for this conversation.
I'm sorry to hear that you have been feeling some distress whilst trying to find pleasure by masturbating. Also it sounds like perhaps you were forced to donate some sperm at a point in your life? Did you want to donate it and it was a necessity of that, or did someone make you? The latter is coercive and really not okay. I'm really sorry if you had to go though that. If you would like to talk about it here we are here to listen.
With your question about methods of masturbation, it is a very common experience for many people to need take time and experiment with what can feel good for them. So whilst it can be frustrating at the time for it to not work right away, know that you are very much not alone here. Also, there is no wrong way to masturbate. Although easier said then done, you don't need to feel like you are "betraying" your experiences of dysphoria by engaging with your body in any kind of way. That said, it is also totally okay to not want to engage with masturbation in a particular way to help avoid triggering any dysphoria.
You may find this article from the daily dot's Trans/Sex
column a useful read, as it touches on the points you have raised: https://www.dailydot.com/irl/trans-sex-masturbation/
Also, it may help to have some more information about how your brain is a really important part of our sexual response cycle: when we're stressed, or putting pressure on ourselves to reach orgasm, or feeling like we 'should' masturbate but not really want to, these are all things that are counteractive to experiencing pleasure for masturbation as our brain instead focuses on the stress we are feeling. Therefore it might be useful to instead explore pleasure more from a curiosity mindset, this could be a really gentle way to begin to explore pleasure for yourself (eg. what kind of sensations and activities do you enjoy generally, how do certain kinds of touch make you feel rather than trying to make them trigger a sexual response). Could that sound good for you? It's also totally fine to focus on other kinds of activities or take a break from trying masturbation for as long as you need, too.
Here are a couple of articles that go into more depth about this that you might find useful. If you feel comfortable sharing any thoughts or curiosities that arise for you reading them, we'd be really happy to discuss them with you here.