Hello and welcome to the boards, Doomstroyer!
I don't think I can answer your question about better options for masturbation, simply because no objective better or best way exists --different people like different things. However, we do have resources that cover some ways you can masturbate, if you would like ideas. Experimenting with different kinds of stimulation should help you find options you enjoy more:
I'm not surprised that it is more difficult to feel aroused when you only rely on your imagination--with pornography and with your boyfriend, you just have more to engage your attention and senses. The good thing is that imagination is a skill like any other. With some time and practice, it will likely get easier to feel aroused this way. Try to notice and remember the things that you enjoy, so you can use those memories as a starting point for when you are fantasizing on your own. You don't have to watch pornography if you don't want to, of course, but if you do, pausing and practicing letting your imagination fill in the gaps may also help.
I want to share two more articles of ours that talk about engaging with imagination and fantasy:
I’m not addicted to porn
I think I can guess at what you mean by this: that you don't feel uncontrolled about your use of pornography, or like it is a problem that interferes with your life. Is that right?
Just for your information, I want to share that we don't usually use the framework of addiction to describe the issues that people can have with pornography or sex here. This is because, when people are engaging with porn in ways that don't serve them, the issue isn't usually the media itself. Rather they might (for example) be using it as a coping mechanism or distraction for something that bothers them. Framing pornography itself as addictive can obfuscate the actual reasons why someone might engage with it, and contribute to the stigma people have against sexual media.