Attention experienced bottoms

How do I do this? 😭 I just ended a ltr last year (6years) but I haven’t bottomed in like 4 years. I never much cared for it, and my ex preferred to bottom so it worked out. I recently just started dating this guy and I’m in love with him. Like I’ve never had this kind of chemistry and he’s obsessed with my ass and wants to top me and it’s honestly a huge turn on, but his dick is huge 😭. We fool around and he’ll put the tip in but it’s too much even then. I need advice. As much as you can give me. I take psyllium husk daily for the fiber intake but just for health reasons not for bottoming. I literally don’t know how to douche, and I don’t know how to get over the pain of it. The idea of bottoming for him is such a turn on, and I want to submit for him, but I’m genuinely terrified of it. I’ve tried poppers and I never want to touch them again. I’m not a fan.