Can't work out if porn warped me or I genuinely want this

I'll start this by saying I'm currently in a straight long term relationship, but over time I've slowly wanted more and more to be a total slut bottom for once, especially when I'm horny, for an extremely hung guy.

I have no idea what it is but I can't shake it. Won't deny my porn consumption is very heavy, but it doesn't matter how much I try and detox from it or go away. The urges always resurface somewhere. When I get horny now all I can think about is what it'd feel like to be completely dominated by a top with a huge cock. I'd probably be caged so I could only touch his cock. Having him make comparisons between them makes me go crazy. Feel like I need to experience this, but I also hate the thought of it once I've cum and go completely off the idea...