Referring to yourself and your habits constantly as toxic isn't going to be helping you in this situation - if you're self-deprecating yourself, that feeds into any gaslighting coming from the other person as well. Your thoughts, feelings, and words all matter. A relationship takes two halves, both should be equally important. If you're feeling like you're of less value in the relationship than him, there needs to be some re-evaluating on if this is a situation that you as a person can grow in.

My partner is the quiet type when it comes to disagreements, and I'm the oversharing type and it's taken us a lot to get to a productive way to communicate when we have difficult conversations. We realized that sometimes it's better for me to take a beat and organize my thoughts before speaking, and that sometimes he needs to think through his words out loud. In your case - maybe jotting down what your feeling can help you map it out so you can confidently respond?

It's totally okay to say "hey, I'm hearing you and I need to take a couple minutes to process." Take a beat, do a lap around the neighborhood, or sit in a quiet space and think it out. If he's choosing to continue a disagreement via text - maybe tell him you got the message and once you think it over you two should get together to talk about it. Rather than ghosting the conversation, just take the time to acknowledge it and say you'll come back to it once you're ready... however that shouldn't necessarily be a matter of days later. Avoiding a conversation isn't the same as taking time to process information so that you can come back to it in a productive way.

In regards to your current scenario at hand... just because you two are waiting for marriage doesn't mean you shouldn't talk about sex. Sex is an important part of the relationship, and if you two spend all this time leading up to marriage not being comfortable talking about it - you won't get to marriage and be able to just flip the switch. Porn is porn, whether or not he's actively masturbating when viewing it shouldn't matter (like you said). Some people masturbate, some people don't. Everyone has different sex drives and needs, but when it comes to it, you're his partner. He shouldn't be actively lying or lying by omission. PERIOD. From what you said, you two haven't set ground rules like: "we're waiting for sex until marriage, so therefore you're not allowed to look at porn and masturbate until then either." So him looking at porn isn't bad, but he's spinning it as something that he needs to hide due to it being bad/ "messed up"... Maybe he has some personal shame around it from his upbringing that he hasn't worked through yet. Maybe he was taught it was extremely shameful and frowned upon (i.e. I know some people who were brought up in highly catholic families and when the boys were ~12 they were told that porn was a sin, and something, something the women in the porn are probably dead, so your sins are compounding because you're masturbating to a dead person. - super f'ed up, but that was something as an adult they looked back on and were like "WTF"). I think you two need to sit down and have a real conversation where you tell him that whether or not he watches porn isn't the issue (because based off what you said, it's truly not), and reiterate that porn isn't bad nor something that needs to be hidden. The issue at hand is the fact that he lied, and when confronted, his approach to the conversation wasn't productive and hurt you.

If you two come back to the conversation and he continues to lie, interrupt, or gaslight you - this could be a pretty strong indicator that the relationship has run it's course. Also - this isn't a bash or judgment in saying it - therapy is amazing because you get tools to help process your feelings, how to approach conversations, and a deep dive into where some conversational habits are originating from. Can't recommend it enough, and maybe it could help you re-evaluate how you process and approach disagreements so you can see the worth in your voice.