Sorry if this isn't allowed here, I figured this would be a good place to get advice.

I bought a buttplug that's 57mm diameter, and I thought it would be okay since I have a dildo that is similar but apparently it isn't okay at all haha. It does not fit at all, I can get it to almost the widest part of plug and then it refuses to move any further. I do think if I kept doing this it would go in but I'm scared of it getting stuck although I haven't experienced any pain at all, it just feels like it hits a brick wall and won't go any further lol.

Does anyone have any suggestions for getting up to the size of the plug? Or do I just need to get a smaller one?