Help! Baby refuses crib at night

Hi all, so last night my 4 month old lost her mind when we tried to put her to bed in her crib in her own room at night for the first time. She has been taking naps very well in her crib for a month now. Since birth she has only ever slept in her bassinet next to me for night. She’s getting too long for the bassinet so we decided to try to make the switch....we are wiped out this morning. She has been sleeping through the night since 2 months old (only wakes for one feeding and occasionally gets fussy to have her pacifier put back in). But last night she woke screaming every hour. She was very difficult to console even with rocking or breastfeeding. She did not have a temperature (we checked multiple times with the thermometer). She just saw the pediatrician last week and said no teeth buds yet. She was acting fine all day and is acting her normal happy self this morning. I’m guessing she woke up in a seemingly unfamiliar place and just worked herself up so much that she screamed every hour (she did this even after we caved and put her back in the bassinet around midnight).

What did you do to help baby transition? We still swaddled her the same, we used the same white noise machine, breastfed right before bed....essentially tried to keep everything the same with just a location change. I will say in the bassinet she likes to sleep against the side of it whereas for naps in the crib she sleeps in the middle. Maybe she felt scared when she woke and couldn’t feel the side of her bassinet up against her? What do I do for that and still practice safe sleep?

Side note: pediatrician told us to start feeding rice cereal. We tried it with her for the first time yesterday. After reading some things online, I’m wondering if that was the culprit and not the transition to the crib. Have others had this experience with starting a 4 month old on rice cereal?