Tips on proper anal dilation to prevent pain?

For context, my boyfriend and I finally decided to try penetration and we each wanted to try being top and bottom. I managed to top him, but I couldn't bottom because I started feeling pain.Our plan was to start with one finger, then a small butt plug, then 2 fingers, then a medium plug, then penetration. I managed to get up to the small plug, but when he started inserting 2 fingers, I quickly started feeling a sharp burning sensation that really hurt so we had to stop. We used a ton of lube, and did so very slowly, but it happened every time we tried. I've also felt pain when we he fingers me with two, but one finger feels amazing.So the point of the post is to ask for tips on how to dilate properly and do so in such a way that it doesn't cause this sort of pain so that we can both enjoy it. Honestly, I need to dilate more than he does because he has a thicker and larger penis, so I need to get up to at least the medium plug without pain. Tips?TL;DR: Help me be bottom without it hurting, because right now even 2 fingers hurts me a lot.